diff --git a/caffeine/src/jmh/java/com/github/benmanes/caffeine/cache/BasicCache.java b/caffeine/src/jmh/java/com/github/benmanes/caffeine/cache/BasicCache.java
index 22eaf1448b..d65f20dcc8 100644
--- a/caffeine/src/jmh/java/com/github/benmanes/caffeine/cache/BasicCache.java
+++ b/caffeine/src/jmh/java/com/github/benmanes/caffeine/cache/BasicCache.java
@@ -15,7 +15,6 @@
  */
 package com.github.benmanes.caffeine.cache;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -26,13 +25,13 @@
 public interface BasicCache<K, V> {
 
   /** Returns the value stored in the cache, or null if not present. */
-  @Nullable V get(@NonNull K key);
+  @Nullable V get(K key);
 
   /** Stores the value into the cache, replacing an existing mapping if present. */
-  void put(@NonNull K key, @NonNull V value);
+  void put(K key, V value);
 
   /** Removes the entry from the cache, if present. */
-  void remove(@NonNull K key);
+  void remove(K key);
 
   /** Invalidates all entries from the cache. */
   void clear();
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCache.java
index 19571ed2ce..ce4b0135de 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCache.java
@@ -23,7 +23,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -50,7 +49,7 @@ public interface AsyncCache<K, V> {
    * @throws NullPointerException if the specified key is null
    */
   @Nullable
-  CompletableFuture<V> getIfPresent(@NonNull K key);
+  CompletableFuture<V> getIfPresent(K key);
 
   /**
    * Returns the future associated with {@code key} in this cache, obtaining that value from
@@ -70,9 +69,7 @@ public interface AsyncCache<K, V> {
    * @return the current (existing or computed) future value associated with the specified key
    * @throws NullPointerException if the specified key or mappingFunction is null
    */
-  @NonNull
-  CompletableFuture<V> get(@NonNull K key,
-      @NonNull Function<? super K, ? extends V> mappingFunction);
+  CompletableFuture<V> get(K key, Function<? super K, ? extends V> mappingFunction);
 
   /**
    * Returns the future associated with {@code key} in this cache, obtaining that value from
@@ -95,9 +92,8 @@ CompletableFuture<V> get(@NonNull K key,
    * @throws RuntimeException or Error if the mappingFunction does when constructing the future,
    *         in which case the mapping is left unestablished
    */
-  @NonNull
-  CompletableFuture<V> get(@NonNull K key,
-      @NonNull BiFunction<? super K, Executor, CompletableFuture<V>> mappingFunction);
+  CompletableFuture<V> get(K key,
+      BiFunction<? super K, Executor, CompletableFuture<V>> mappingFunction);
 
   /**
    * Returns the future of a map of the values associated with {@code keys}, creating or retrieving
@@ -122,9 +118,8 @@ CompletableFuture<V> get(@NonNull K key,
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys,
-      @NonNull Function<Set<? extends @NonNull K>, @NonNull Map<K, V>> mappingFunction);
+  CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys,
+      Function<Set<? extends K>, Map<K, V>> mappingFunction);
 
   /**
    * Returns the future of a map of the values associated with {@code keys}, creating or retrieving
@@ -149,9 +144,8 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys,
-      @NonNull BiFunction<Set<? extends @NonNull K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction);
+  CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys,
+      BiFunction<Set<? extends K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction);
 
   /**
    * Associates {@code value} with {@code key} in this cache. If the cache previously contained a
@@ -165,7 +159,7 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    * @param valueFuture value to be associated with the specified key
    * @throws NullPointerException if the specified key or value is null
    */
-  void put(@NonNull K key, @NonNull CompletableFuture<V> valueFuture);
+  void put(K key, CompletableFuture<V> valueFuture);
 
   /**
    * Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to
@@ -182,8 +176,7 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    *
    * @return a thread-safe view of this cache supporting all of the optional {@link Map} operations
    */
-  @NonNull
-  ConcurrentMap<@NonNull K, @NonNull CompletableFuture<V>> asMap();
+  ConcurrentMap<K, CompletableFuture<V>> asMap();
 
   /**
    * Returns a view of the entries stored in this cache as a synchronous {@link Cache}. A mapping is
@@ -193,6 +186,5 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    *
    * @return a thread-safe synchronous view of this cache
    */
-  @NonNull
   Cache<K, V> synchronous();
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java
index a3665d601e..ae5e09aa47 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java
@@ -24,8 +24,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * Computes or retrieves values asynchronously, based on a key, for use in populating a
  * {@link AsyncLoadingCache}.
@@ -57,8 +55,7 @@ public interface AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  CompletableFuture<V> asyncLoad(@NonNull K key, @NonNull Executor executor) throws Exception;
+  CompletableFuture<V> asyncLoad(K key, Executor executor) throws Exception;
 
   /**
    * Asynchronously computes or retrieves the values corresponding to {@code keys}. This method is
@@ -82,9 +79,8 @@ public interface AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  default CompletableFuture<Map<@NonNull K, @NonNull V>> asyncLoadAll(
-      @NonNull Set<? extends @NonNull K> keys, @NonNull Executor executor) throws Exception {
+  default CompletableFuture<Map<K, V>> asyncLoadAll(
+      Set<? extends K> keys, Executor executor) throws Exception {
     throw new UnsupportedOperationException();
   }
 
@@ -106,9 +102,7 @@ public interface AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  default CompletableFuture<V> asyncReload(
-      @NonNull K key, @NonNull V oldValue, @NonNull Executor executor) throws Exception {
+  default CompletableFuture<V> asyncReload(K key, V oldValue, Executor executor) throws Exception {
     return asyncLoad(key, executor);
   }
 
@@ -128,7 +122,6 @@ default CompletableFuture<V> asyncReload(
    * @return an asynchronous cache loader that delegates to the supplied {@code mappingFunction}
    * @throws NullPointerException if the mappingFunction is null
    */
-  @NonNull
   static <K, V> AsyncCacheLoader<K, V> bulk(Function<Set<? extends K>, Map<K, V>> mappingFunction) {
     return CacheLoader.bulk(mappingFunction);
   }
@@ -149,7 +142,6 @@ static <K, V> AsyncCacheLoader<K, V> bulk(Function<Set<? extends K>, Map<K, V>>
    * @return an asynchronous cache loader that delegates to the supplied {@code mappingFunction}
    * @throws NullPointerException if the mappingFunction is null
    */
-  @NonNull
   static <K, V> AsyncCacheLoader<K, V> bulk(
       BiFunction<Set<? extends K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction) {
     requireNonNull(mappingFunction);
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java
index 68c50a989e..4e1110e855 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java
@@ -18,8 +18,6 @@
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * A semi-persistent mapping from keys to values. Values are automatically loaded by the cache
  * asynchronously, and are stored in the cache until either evicted or manually invalidated.
@@ -49,8 +47,7 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    * @throws RuntimeException or Error if the {@link AsyncCacheLoader} does when constructing the
    *         future, in which case the mapping is left unestablished
    */
-  @NonNull
-  CompletableFuture<V> get(@NonNull K key);
+  CompletableFuture<V> get(K key);
 
   /**
    * Returns the future of a map of the values associated with {@code keys}, creating or retrieving
@@ -78,8 +75,7 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    *         {@link AsyncCacheLoader#asyncLoadAll} returns {@code null}, or fails when constructing
    *         the future, in which case the mapping is left unestablished
    */
-  @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys);
+  CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys);
 
   /**
    * Returns a view of the entries stored in this cache as a synchronous {@link LoadingCache}. A
@@ -89,7 +85,6 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    *
    * @return a thread-safe synchronous view of this cache
    */
-  @NonNull
   @Override
   LoadingCache<K, V> synchronous();
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java
index 68b1cc2d3d..8adf9dab65 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java
@@ -70,7 +70,6 @@
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.Async.AsyncExpiry;
@@ -752,13 +751,13 @@ void evictFromMain(int candidates) {
       K victimKey = victim.getKey();
       K candidateKey = candidate.getKey();
       if (victimKey == null) {
-        @NonNull Node<K, V> evict = victim;
+        Node<K, V> evict = victim;
         victim = victim.getNextInAccessOrder();
         evictEntry(evict, RemovalCause.COLLECTED, 0L);
         continue;
       } else if (candidateKey == null) {
         candidates--;
-        @NonNull Node<K, V> evict = candidate;
+        Node<K, V> evict = candidate;
         candidate = candidate.getPreviousInAccessOrder();
         evictEntry(evict, RemovalCause.COLLECTED, 0L);
         continue;
@@ -3524,7 +3523,7 @@ final class BoundedEviction implements Eviction<K, V> {
       @Override public boolean isWeighted() {
         return isWeighted;
       }
-      @Override public OptionalInt weightOf(@NonNull K key) {
+      @Override public OptionalInt weightOf(K key) {
         requireNonNull(key);
         if (!isWeighted) {
           return OptionalInt.empty();
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Buffer.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Buffer.java
index 221f91ff1e..ba497e8c9a 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Buffer.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Buffer.java
@@ -17,8 +17,6 @@
 
 import java.util.function.Consumer;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * A multiple-producer / single-consumer buffer that rejects new elements if it is full or
  * fails spuriously due to contention. Unlike a queue and stack, a buffer does not guarantee an
@@ -50,7 +48,7 @@ static <E> Buffer<E> disabled() {
    * @param e the element to add
    * @return {@code 1} if the buffer is full, {@code -1} if the CAS failed, or {@code 0} if added
    */
-  int offer(@NonNull E e);
+  int offer(E e);
 
   /**
    * Drains the buffer, sending each element to the consumer for processing. The caller must ensure
@@ -58,7 +56,7 @@ static <E> Buffer<E> disabled() {
    *
    * @param consumer the action to perform on each element
    */
-  void drainTo(@NonNull Consumer<E> consumer);
+  void drainTo(Consumer<E> consumer);
 
   /**
    * Returns the number of elements residing in the buffer.
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java
index ce80c14cc9..897ceffce9 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java
@@ -21,8 +21,8 @@
 import java.util.function.Function;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.checker.nullness.qual.PolyNull;
 
 import com.github.benmanes.caffeine.cache.stats.CacheStats;
 
@@ -50,7 +50,7 @@ public interface Cache<K, V> {
    * @throws NullPointerException if the specified key is null
    */
   @Nullable
-  V getIfPresent(@NonNull K key);
+  V getIfPresent(K key);
 
   /**
    * Returns the value associated with the {@code key} in this cache, obtaining that value from the
@@ -77,8 +77,8 @@ public interface Cache<K, V> {
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @Nullable
-  V get(@NonNull K key, @NonNull Function<? super K, ? extends V> mappingFunction);
+  @PolyNull
+  V get(K key, Function<? super K, ? extends @PolyNull V> mappingFunction);
 
   /**
    * Returns a map of the values associated with the {@code keys} in this cache. The returned map
@@ -91,8 +91,7 @@ public interface Cache<K, V> {
    * @return the unmodifiable mapping of keys to values for the specified keys found in this cache
    * @throws NullPointerException if the specified collection is null or contains a null element
    */
-  @NonNull
-  Map<@NonNull K, @NonNull V> getAllPresent(@NonNull Iterable<? extends K> keys);
+  Map<K, V> getAllPresent(Iterable<? extends K> keys);
 
   /**
    * Returns a map of the values associated with the {@code keys}, creating or retrieving those
@@ -118,9 +117,8 @@ public interface Cache<K, V> {
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @NonNull
-  Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
-      @NonNull Function<Set<? extends @NonNull K>, @NonNull Map<K, V>> mappingFunction);
+  Map<K, V> getAll(Iterable<? extends K> keys,
+      Function<Set<? extends K>, Map<K, V>> mappingFunction);
 
   /**
    * Associates the {@code value} with the {@code key} in this cache. If the cache previously
@@ -134,7 +132,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @param value value to be associated with the specified key
    * @throws NullPointerException if the specified key or value is null
    */
-  void put(@NonNull K key, @NonNull V value);
+  void put(K key, V value);
 
   /**
    * Copies all of the mappings from the specified map to the cache. The effect of this call is
@@ -146,7 +144,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @throws NullPointerException if the specified map is null or the specified map contains null
    *         keys or values
    */
-  void putAll(@NonNull Map<? extends @NonNull K,? extends @NonNull V> map);
+  void putAll(Map<? extends K,? extends V> map);
 
   /**
    * Discards any cached value for the {@code key}. The behavior of this operation is undefined for
@@ -155,7 +153,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @param key the key whose mapping is to be removed from the cache
    * @throws NullPointerException if the specified key is null
    */
-  void invalidate(@NonNull K key);
+  void invalidate(K key);
 
   /**
    * Discards any cached values for the {@code keys}. The behavior of this operation is undefined
@@ -164,7 +162,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @param keys the keys whose associated values are to be removed
    * @throws NullPointerException if the specified collection is null or contains a null element
    */
-  void invalidateAll(@NonNull Iterable<? extends @NonNull K> keys);
+  void invalidateAll(Iterable<? extends K> keys);
 
   /**
    * Discards all entries in the cache. The behavior of this operation is undefined for an entry
@@ -192,7 +190,6 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    *
    * @return the current snapshot of the statistics of this cache
    */
-  @NonNull
   CacheStats stats();
 
   /**
@@ -210,8 +207,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    *
    * @return a thread-safe view of this cache supporting all of the optional {@link Map} operations
    */
-  @NonNull
-  ConcurrentMap<@NonNull K, @NonNull V> asMap();
+  ConcurrentMap<K, V> asMap();
 
   /**
    * Performs any pending maintenance operations needed by the cache. Exactly which activities are
@@ -226,6 +222,5 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    *
    * @return access to inspect and perform advanced operations based on the cache's characteristics
    */
-  @NonNull
   Policy<K, V> policy();
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java
index 9420e68165..984d8002e6 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java
@@ -24,7 +24,6 @@
 import java.util.concurrent.Executor;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -59,7 +58,7 @@ public interface CacheLoader<K, V> extends AsyncCacheLoader<K, V> {
    *         caught, the thread's interrupt status is set
    */
   @Nullable
-  V load(@NonNull K key) throws Exception;
+  V load(K key) throws Exception;
 
   /**
    * Computes or retrieves the values corresponding to {@code keys}. This method is called by
@@ -84,9 +83,7 @@ public interface CacheLoader<K, V> extends AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  default Map<@NonNull K, @NonNull V> loadAll(
-      @NonNull Set<? extends @NonNull K> keys) throws Exception {
+  default Map<K, V> loadAll(Set<? extends K> keys) throws Exception {
     throw new UnsupportedOperationException();
   }
 
@@ -97,8 +94,8 @@ public interface CacheLoader<K, V> extends AsyncCacheLoader<K, V> {
    * @param executor the executor that asynchronously loads the entry
    * @return the future value associated with {@code key}
    */
-  @Override @NonNull
-  default CompletableFuture<V> asyncLoad(@NonNull K key, @NonNull Executor executor) {
+  @Override
+  default CompletableFuture<V> asyncLoad(K key, Executor executor) {
     requireNonNull(key);
     requireNonNull(executor);
     return CompletableFuture.supplyAsync(() -> {
@@ -130,9 +127,8 @@ default CompletableFuture<V> asyncLoad(@NonNull K key, @NonNull Executor executo
    * @return a future containing the map from each key in {@code keys} to the value associated with
    *         that key; <b>may not contain null values</b>
    */
-  @Override @NonNull
-  default CompletableFuture<Map<@NonNull K, @NonNull V>> asyncLoadAll(
-      @NonNull Set<? extends K> keys, @NonNull Executor executor) {
+  @Override
+  default CompletableFuture<Map<K, V>> asyncLoadAll(Set<? extends K> keys, Executor executor) {
     requireNonNull(keys);
     requireNonNull(executor);
     return CompletableFuture.supplyAsync(() -> {
@@ -164,7 +160,7 @@ default CompletableFuture<V> asyncLoad(@NonNull K key, @NonNull Executor executo
    *         caught, the thread's interrupt status is set
    */
   @Nullable
-  default V reload(@NonNull K key, @NonNull V oldValue) throws Exception {
+  default V reload(K key, V oldValue) throws Exception {
     return load(key);
   }
 
@@ -182,9 +178,8 @@ default V reload(@NonNull K key, @NonNull V oldValue) throws Exception {
    * @return a future containing the new value associated with {@code key}, or containing
    *         {@code null} if the mapping is to be removed
    */
-  @Override @NonNull
-  default CompletableFuture<V> asyncReload(
-      @NonNull K key, @NonNull V oldValue, @NonNull Executor executor) throws Exception {
+  @Override
+  default CompletableFuture<V> asyncReload(K key, V oldValue, Executor executor) throws Exception {
     requireNonNull(key);
     requireNonNull(executor);
     return CompletableFuture.supplyAsync(() -> {
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheWriter.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheWriter.java
index 88122a6dab..2a7890bdf3 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheWriter.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheWriter.java
@@ -15,7 +15,6 @@
  */
 package com.github.benmanes.caffeine.cache;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -40,7 +39,7 @@ public interface CacheWriter<K, V> {
    * @param value the value associated with {@code key} that should be written
    * @throws RuntimeException or Error, in which case the mapping is unchanged
    */
-  void write(@NonNull K key, @NonNull V value);
+  void write(K key, V value);
 
   /**
    * Deletes the value corresponding to the {@code key} from the external resource. The cache will
@@ -51,7 +50,7 @@ public interface CacheWriter<K, V> {
    * @param cause the reason for which the entry was removed
    * @throws RuntimeException or Error, in which case the mapping is unchanged
    */
-  void delete(@NonNull K key, @Nullable V value, @NonNull RemovalCause cause);
+  void delete(K key, @Nullable V value, RemovalCause cause);
 
   /**
    * Returns a writer that does nothing.
@@ -60,7 +59,7 @@ public interface CacheWriter<K, V> {
    * @param <V> the type of values
    * @return a writer that performs no operations
    */
-  static @NonNull <K, V> CacheWriter<K, V> disabledWriter() {
+  static <K, V> CacheWriter<K, V> disabledWriter() {
     @SuppressWarnings("unchecked")
     CacheWriter<K, V> writer = (CacheWriter<K, V>) DisabledWriter.INSTANCE;
     return writer;
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java
index b480aa898d..d9a5070fe9 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java
@@ -36,7 +36,6 @@
 import java.util.function.Supplier;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.Async.AsyncExpiry;
@@ -221,7 +220,6 @@ static long ceilingPowerOfTwo(long x) {
    *
    * @return a new instance with default settings
    */
-  @NonNull
   public static Caffeine<Object, Object> newBuilder() {
     return new Caffeine<>();
   }
@@ -232,7 +230,6 @@ public static Caffeine<Object, Object> newBuilder() {
    * @param spec the specification to build from
    * @return a new instance with the specification's settings
    */
-  @NonNull
   public static Caffeine<Object, Object> from(CaffeineSpec spec) {
     Caffeine<Object, Object> builder = spec.toBuilder();
     builder.strictParsing = false;
@@ -245,7 +242,6 @@ public static Caffeine<Object, Object> from(CaffeineSpec spec) {
    * @param spec a String in the format specified by {@link CaffeineSpec}
    * @return a new instance with the specification's settings
    */
-  @NonNull
   public static Caffeine<Object, Object> from(String spec) {
     return from(CaffeineSpec.parse(spec));
   }
@@ -260,7 +256,6 @@ public static Caffeine<Object, Object> from(String spec) {
    * @throws IllegalArgumentException if {@code initialCapacity} is negative
    * @throws IllegalStateException if an initial capacity was already set
    */
-  @NonNull
   public Caffeine<K, V> initialCapacity(@NonNegative int initialCapacity) {
     requireState(this.initialCapacity == UNSET_INT,
         "initial capacity was already set to %s", this.initialCapacity);
@@ -294,14 +289,12 @@ int getInitialCapacity() {
    * @return this {@code Caffeine} instance (for chaining)
    * @throws NullPointerException if the specified executor is null
    */
-  @NonNull
-  public Caffeine<K, V> executor(@NonNull Executor executor) {
+  public Caffeine<K, V> executor(Executor executor) {
     requireState(this.executor == null, "executor was already set to %s", this.executor);
     this.executor = requireNonNull(executor);
     return this;
   }
 
-  @NonNull
   Executor getExecutor() {
     return (executor == null) ? ForkJoinPool.commonPool() : executor;
   }
@@ -327,14 +320,12 @@ Executor getExecutor() {
    * @return this {@code Caffeine} instance (for chaining)
    * @throws NullPointerException if the specified scheduler is null
    */
-  @NonNull
-  public Caffeine<K, V> scheduler(@NonNull Scheduler scheduler) {
+  public Caffeine<K, V> scheduler(Scheduler scheduler) {
     requireState(this.scheduler == null, "scheduler was already set to %s", this.scheduler);
     this.scheduler = requireNonNull(scheduler);
     return this;
   }
 
-  @NonNull
   Scheduler getScheduler() {
     if ((scheduler == null) || (scheduler == Scheduler.disabledScheduler())) {
       return Scheduler.disabledScheduler();
@@ -363,7 +354,6 @@ Scheduler getScheduler() {
    * @throws IllegalArgumentException if {@code size} is negative
    * @throws IllegalStateException if a maximum size or weight was already set
    */
-  @NonNull
   public Caffeine<K, V> maximumSize(@NonNegative long maximumSize) {
     requireState(this.maximumSize == UNSET_INT,
         "maximum size was already set to %s", this.maximumSize);
@@ -400,7 +390,6 @@ public Caffeine<K, V> maximumSize(@NonNegative long maximumSize) {
    * @throws IllegalArgumentException if {@code maximumWeight} is negative
    * @throws IllegalStateException if a maximum weight or size was already set
    */
-  @NonNull
   public Caffeine<K, V> maximumWeight(@NonNegative long maximumWeight) {
     requireState(this.maximumWeight == UNSET_INT,
         "maximum weight was already set to %s", this.maximumWeight);
@@ -441,9 +430,8 @@ public Caffeine<K, V> maximumWeight(@NonNegative long maximumWeight) {
    *         remaining configuration and cache building
    * @throws IllegalStateException if a weigher was already set
    */
-  @NonNull
   public <K1 extends K, V1 extends V> Caffeine<K1, V1> weigher(
-      @NonNull Weigher<? super K1, ? super V1> weigher) {
+      Weigher<? super K1, ? super V1> weigher) {
     requireNonNull(weigher);
     requireState(this.weigher == null, "weigher was already set to %s", this.weigher);
     requireState(!strictParsing || this.maximumSize == UNSET_INT,
@@ -467,7 +455,7 @@ long getMaximum() {
     return isWeighted() ? maximumWeight : maximumSize;
   }
 
-  @NonNull @SuppressWarnings({"unchecked", "rawtypes"})
+  @SuppressWarnings({"unchecked", "rawtypes"})
   <K1 extends K, V1 extends V> Weigher<K1, V1> getWeigher(boolean isAsync) {
     Weigher<K1, V1> delegate = (weigher == null) || (weigher == Weigher.singletonWeigher())
         ? Weigher.singletonWeigher()
@@ -493,7 +481,6 @@ <K1 extends K, V1 extends V> Weigher<K1, V1> getWeigher(boolean isAsync) {
    * @return this {@code Caffeine} instance (for chaining)
    * @throws IllegalStateException if the key strength was already set or the writer was set
    */
-  @NonNull
   public Caffeine<K, V> weakKeys() {
     requireState(keyStrength == null, "Key strength was already set to %s", keyStrength);
     requireState(writer == null, "Weak keys may not be used with CacheWriter");
@@ -525,7 +512,6 @@ boolean isStrongKeys() {
    * @return this {@code Caffeine} instance (for chaining)
    * @throws IllegalStateException if the value strength was already set
    */
-  @NonNull
   public Caffeine<K, V> weakValues() {
     requireState(valueStrength == null, "Value strength was already set to %s", valueStrength);
     valueStrength = Strength.WEAK;
@@ -562,7 +548,6 @@ boolean isWeakValues() {
    * @return this {@code Caffeine} instance (for chaining)
    * @throws IllegalStateException if the value strength was already set
    */
-  @NonNull
   public Caffeine<K, V> softValues() {
     requireState(valueStrength == null, "Value strength was already set to %s", valueStrength);
     valueStrength = Strength.SOFT;
@@ -584,8 +569,7 @@ public Caffeine<K, V> softValues() {
    * @throws IllegalStateException if the time to live or time to idle was already set
    * @throws ArithmeticException for durations greater than +/- approximately 292 years
    */
-  @NonNull
-  public Caffeine<K, V> expireAfterWrite(@NonNull Duration duration) {
+  public Caffeine<K, V> expireAfterWrite(Duration duration) {
     return expireAfterWrite(saturatedToNanos(duration), TimeUnit.NANOSECONDS);
   }
 
@@ -607,8 +591,7 @@ public Caffeine<K, V> expireAfterWrite(@NonNull Duration duration) {
    * @throws IllegalArgumentException if {@code duration} is negative
    * @throws IllegalStateException if the time to live or variable expiration was already set
    */
-  @NonNull
-  public Caffeine<K, V> expireAfterWrite(@NonNegative long duration, @NonNull TimeUnit unit) {
+  public Caffeine<K, V> expireAfterWrite(@NonNegative long duration, TimeUnit unit) {
     requireState(expireAfterWriteNanos == UNSET_INT,
         "expireAfterWrite was already set to %s ns", expireAfterWriteNanos);
     requireState(expiry == null, "expireAfterWrite may not be used with variable expiration");
@@ -643,8 +626,7 @@ boolean expiresAfterWrite() {
    * @throws IllegalStateException if the time to idle or time to live was already set
    * @throws ArithmeticException for durations greater than +/- approximately 292 years
    */
-  @NonNull
-  public Caffeine<K, V> expireAfterAccess(@NonNull Duration duration) {
+  public Caffeine<K, V> expireAfterAccess(Duration duration) {
     return expireAfterAccess(saturatedToNanos(duration), TimeUnit.NANOSECONDS);
   }
 
@@ -669,8 +651,7 @@ public Caffeine<K, V> expireAfterAccess(@NonNull Duration duration) {
    * @throws IllegalArgumentException if {@code duration} is negative
    * @throws IllegalStateException if the time to idle or variable expiration was already set
    */
-  @NonNull
-  public Caffeine<K, V> expireAfterAccess(@NonNegative long duration, @NonNull TimeUnit unit) {
+  public Caffeine<K, V> expireAfterAccess(@NonNegative long duration, TimeUnit unit) {
     requireState(expireAfterAccessNanos == UNSET_INT,
         "expireAfterAccess was already set to %s ns", expireAfterAccessNanos);
     requireState(expiry == null, "expireAfterAccess may not be used with variable expiration");
@@ -704,9 +685,8 @@ boolean expiresAfterAccess() {
    * @return this {@code Caffeine} instance (for chaining)
    * @throws IllegalStateException if expiration was already set
    */
-  @NonNull
   public <K1 extends K, V1 extends V> Caffeine<K1, V1> expireAfter(
-      @NonNull Expiry<? super K1, ? super V1> expiry) {
+      Expiry<? super K1, ? super V1> expiry) {
     requireNonNull(expiry);
     requireState(this.expiry == null, "Expiry was already set to %s", this.expiry);
     requireState(this.expireAfterAccessNanos == UNSET_INT,
@@ -750,8 +730,7 @@ boolean expiresVariable() {
    * @throws IllegalStateException if the refresh interval was already set
    * @throws ArithmeticException for durations greater than +/- approximately 292 years
    */
-  @NonNull
-  public Caffeine<K, V> refreshAfterWrite(@NonNull Duration duration) {
+  public Caffeine<K, V> refreshAfterWrite(Duration duration) {
     return refreshAfterWrite(saturatedToNanos(duration), TimeUnit.NANOSECONDS);
   }
 
@@ -777,8 +756,7 @@ public Caffeine<K, V> refreshAfterWrite(@NonNull Duration duration) {
    * @throws IllegalArgumentException if {@code duration} is zero or negative
    * @throws IllegalStateException if the refresh interval was already set
    */
-  @NonNull
-  public Caffeine<K, V> refreshAfterWrite(@NonNegative long duration, @NonNull TimeUnit unit) {
+  public Caffeine<K, V> refreshAfterWrite(@NonNegative long duration, TimeUnit unit) {
     requireNonNull(unit);
     requireState(refreshAfterWriteNanos == UNSET_INT,
         "refreshAfterWriteNanos was already set to %s ns", refreshAfterWriteNanos);
@@ -807,14 +785,12 @@ boolean refreshAfterWrite() {
    * @throws IllegalStateException if a ticker was already set
    * @throws NullPointerException if the specified ticker is null
    */
-  @NonNull
-  public Caffeine<K, V> ticker(@NonNull Ticker ticker) {
+  public Caffeine<K, V> ticker(Ticker ticker) {
     requireState(this.ticker == null, "Ticker was already set to %s", this.ticker);
     this.ticker = requireNonNull(ticker);
     return this;
   }
 
-  @NonNull
   Ticker getTicker() {
     boolean useTicker = expiresVariable() || expiresAfterAccess()
         || expiresAfterWrite() || refreshAfterWrite() || isRecordingStats();
@@ -848,9 +824,8 @@ Ticker getTicker() {
    * @throws IllegalStateException if a removal listener was already set
    * @throws NullPointerException if the specified removal listener is null
    */
-  @NonNull
   public <K1 extends K, V1 extends V> Caffeine<K1, V1> removalListener(
-      @NonNull RemovalListener<? super K1, ? super V1> removalListener) {
+      RemovalListener<? super K1, ? super V1> removalListener) {
     requireState(this.removalListener == null,
         "removal listener was already set to %s", this.removalListener);
 
@@ -896,9 +871,8 @@ public <K1 extends K, V1 extends V> Caffeine<K1, V1> removalListener(
    * @throws IllegalStateException if a writer was already set or if the key strength is weak
    * @throws NullPointerException if the specified writer is null
    */
-  @NonNull
   public <K1 extends K, V1 extends V> Caffeine<K1, V1> writer(
-      @NonNull CacheWriter<? super K1, ? super V1> writer) {
+      CacheWriter<? super K1, ? super V1> writer) {
     requireState(this.writer == null, "Writer was already set to %s", this.writer);
     requireState(keyStrength == null, "Weak keys may not be used with CacheWriter");
 
@@ -922,7 +896,6 @@ <K1 extends K, V1 extends V> CacheWriter<K1, V1> getCacheWriter() {
    *
    * @return this {@code Caffeine} instance (for chaining)
    */
-  @NonNull
   public Caffeine<K, V> recordStats() {
     requireState(this.statsCounterSupplier == null, "Statistics recording was already set");
     statsCounterSupplier = ENABLED_STATS_COUNTER_SUPPLIER;
@@ -939,9 +912,7 @@ public Caffeine<K, V> recordStats() {
    * @param statsCounterSupplier a supplier instance that returns a new {@link StatsCounter}
    * @return this {@code Caffeine} instance (for chaining)
    */
-  @NonNull
-  public Caffeine<K, V> recordStats(
-      @NonNull Supplier<? extends StatsCounter> statsCounterSupplier) {
+  public Caffeine<K, V> recordStats(Supplier<? extends StatsCounter> statsCounterSupplier) {
     requireState(this.statsCounterSupplier == null, "Statistics recording was already set");
     requireNonNull(statsCounterSupplier);
     this.statsCounterSupplier = () -> StatsCounter.guardedStatsCounter(statsCounterSupplier.get());
@@ -952,7 +923,6 @@ boolean isRecordingStats() {
     return (statsCounterSupplier != null);
   }
 
-  @NonNull
   Supplier<StatsCounter> getStatsCounterSupplier() {
     return (statsCounterSupplier == null)
         ? StatsCounter::disabledStatsCounter
@@ -984,7 +954,6 @@ boolean isBounded() {
    * @param <V1> the value type of the cache
    * @return a cache having the requested features
    */
-  @NonNull
   public <K1 extends K, V1 extends V> Cache<K1, V1> build() {
     requireWeightWithWeigher();
     requireNonLoadingCache();
@@ -1010,9 +979,8 @@ public <K1 extends K, V1 extends V> Cache<K1, V1> build() {
    * @param <V1> the value type of the loader
    * @return a cache having the requested features
    */
-  @NonNull
   public <K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
-      @NonNull CacheLoader<? super K1, V1> loader) {
+      CacheLoader<? super K1, V1> loader) {
     requireWeightWithWeigher();
 
     @SuppressWarnings("unchecked")
@@ -1042,7 +1010,6 @@ public <K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
    * @param <V1> the value type of the cache
    * @return a cache having the requested features
    */
-  @NonNull
   public <K1 extends K, V1 extends V> AsyncCache<K1, V1> buildAsync() {
     requireState(valueStrength == null, "Weak or soft values can not be combined with AsyncCache");
     requireState(writer == null, "CacheWriter can not be combined with AsyncCache");
@@ -1074,9 +1041,8 @@ public <K1 extends K, V1 extends V> AsyncCache<K1, V1> buildAsync() {
    * @param <V1> the value type of the loader
    * @return a cache having the requested features
    */
-  @NonNull
   public <K1 extends K, V1 extends V> AsyncLoadingCache<K1, V1> buildAsync(
-      @NonNull CacheLoader<? super K1, V1> loader) {
+      CacheLoader<? super K1, V1> loader) {
     return buildAsync((AsyncCacheLoader<? super K1, V1>) loader);
   }
 
@@ -1098,9 +1064,8 @@ public <K1 extends K, V1 extends V> AsyncLoadingCache<K1, V1> buildAsync(
    * @param <V1> the value type of the loader
    * @return a cache having the requested features
    */
-  @NonNull
   public <K1 extends K, V1 extends V> AsyncLoadingCache<K1, V1> buildAsync(
-      @NonNull AsyncCacheLoader<? super K1, V1> loader) {
+      AsyncCacheLoader<? super K1, V1> loader) {
     requireState(valueStrength == null,
         "Weak or soft values can not be combined with AsyncLoadingCache");
     requireState(writer == null, "CacheWriter can not be combined with AsyncLoadingCache");
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java
index 5c6b4c0e50..346624e68a 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java
@@ -24,7 +24,6 @@
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.Caffeine.Strength;
@@ -142,7 +141,7 @@ Caffeine<Object, Object> toBuilder() {
    * @return the parsed specification
    */
   @SuppressWarnings("StringSplitter")
-  public static @NonNull CaffeineSpec parse(@NonNull String specification) {
+  public static CaffeineSpec parse(String specification) {
     CaffeineSpec spec = new CaffeineSpec(specification);
     for (String option : specification.split(SPLIT_OPTIONS)) {
       spec.parseOption(option.trim());
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java
index 824dee11f4..9d982de2a9 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java
@@ -16,7 +16,6 @@
 package com.github.benmanes.caffeine.cache;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * Calculates when cache entries expire. A single expiration time is retained so that the lifetime
@@ -40,7 +39,7 @@ public interface Expiry<K, V> {
    * @param currentTime the current time, in nanoseconds
    * @return the length of time before the entry expires, in nanoseconds
    */
-  long expireAfterCreate(@NonNull K key, @NonNull V value, long currentTime);
+  long expireAfterCreate(K key, V value, long currentTime);
 
   /**
    * Specifies that the entry should be automatically removed from the cache once the duration has
@@ -58,8 +57,7 @@ public interface Expiry<K, V> {
    * @param currentDuration the current duration, in nanoseconds
    * @return the length of time before the entry expires, in nanoseconds
    */
-  long expireAfterUpdate(@NonNull K key, @NonNull V value,
-      long currentTime, @NonNegative long currentDuration);
+  long expireAfterUpdate(K key, V value, long currentTime, @NonNegative long currentDuration);
 
   /**
    * Specifies that the entry should be automatically removed from the cache once the duration has
@@ -77,6 +75,5 @@ long expireAfterUpdate(@NonNull K key, @NonNull V value,
    * @param currentDuration the current duration, in nanoseconds
    * @return the length of time before the entry expires, in nanoseconds
    */
-  long expireAfterRead(@NonNull K key, @NonNull V value,
-      long currentTime, @NonNegative long currentDuration);
+  long expireAfterRead(K key, V value, long currentTime, @NonNegative long currentDuration);
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java
index fade2fcfbc..fc6d36c113 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java
@@ -18,7 +18,6 @@
 import static com.github.benmanes.caffeine.cache.Caffeine.requireArgument;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * A probabilistic multiset for estimating the popularity of an element within a time window. The
@@ -107,7 +106,7 @@ public boolean isNotInitialized() {
    * @return the estimated number of occurrences of the element; possibly zero but never negative
    */
   @NonNegative
-  public int frequency(@NonNull E e) {
+  public int frequency(E e) {
     if (isNotInitialized()) {
       return 0;
     }
@@ -130,7 +129,7 @@ public int frequency(@NonNull E e) {
    *
    * @param e the element to add
    */
-  public void increment(@NonNull E e) {
+  public void increment(E e) {
     if (isNotInitialized()) {
       return;
     }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java
index 06c9e7f25e..6eaace5ca9 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java
@@ -19,7 +19,6 @@
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -61,7 +60,7 @@ public interface LoadingCache<K, V> extends Cache<K, V> {
    *         is left unestablished
    */
   @Nullable
-  V get(@NonNull K key);
+  V get(K key);
 
   /**
    * Returns a map of the values associated with the {@code keys}, creating or retrieving those
@@ -89,8 +88,7 @@ public interface LoadingCache<K, V> extends Cache<K, V> {
    *         values, or fails to return an entry for each requested key. In all cases, the mapping
    *         is left unestablished
    */
-  @NonNull
-  Map<@NonNull K, @NonNull V> getAll(@NonNull Iterable<? extends @NonNull K> keys);
+  Map<K, V> getAll(Iterable<? extends K> keys);
 
   /**
    * Loads a new value for the {@code key}, asynchronously. While the new value is loading the
@@ -110,6 +108,5 @@ public interface LoadingCache<K, V> extends Cache<K, V> {
    * @return the future that is loading the value
    * @throws NullPointerException if the specified key is null
    */
-  @NonNull
-  CompletableFuture<V> refresh(@NonNull K key);
+  CompletableFuture<V> refresh(K key);
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalAsyncCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalAsyncCache.java
index 1b0adffe8e..0e823c80d8 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalAsyncCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalAsyncCache.java
@@ -41,7 +41,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.LocalAsyncCache.AsyncBulkCompleter.NullMapCompletionException;
@@ -63,13 +62,12 @@ interface LocalAsyncCache<K, V> extends AsyncCache<K, V> {
   Policy<K, V> policy();
 
   @Override
-  default @Nullable CompletableFuture<V> getIfPresent(@NonNull K key) {
+  default @Nullable CompletableFuture<V> getIfPresent(K key) {
     return cache().getIfPresent(key, /* recordStats */ true);
   }
 
   @Override
-  default CompletableFuture<V> get(@NonNull K key,
-      @NonNull Function<? super K, ? extends V> mappingFunction) {
+  default CompletableFuture<V> get(K key, Function<? super K, ? extends V> mappingFunction) {
     requireNonNull(mappingFunction);
     return get(key, (k1, executor) -> CompletableFuture.supplyAsync(
         () -> mappingFunction.apply(key), executor));
@@ -98,7 +96,7 @@ default CompletableFuture<V> get(K key,
   }
 
   @Override
-  default CompletableFuture<Map<K, V>> getAll(Iterable<? extends @NonNull K> keys,
+  default CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys,
       Function<Set<? extends K>, Map<K, V>> mappingFunction) {
     requireNonNull(mappingFunction);
     return getAll(keys, (keysToLoad, executor) ->
@@ -107,7 +105,7 @@ default CompletableFuture<Map<K, V>> getAll(Iterable<? extends @NonNull K> keys,
 
   @Override
   @SuppressWarnings("FutureReturnValueIgnored")
-  default CompletableFuture<Map<K, V>> getAll(Iterable<? extends @NonNull K> keys,
+  default CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys,
       BiFunction<Set<? extends K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction) {
     requireNonNull(mappingFunction);
     requireNonNull(keys);
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalCache.java
index 03e16508d7..7b470c04fb 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalCache.java
@@ -22,7 +22,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.stats.StatsCounter;
@@ -39,7 +38,7 @@ interface LocalCache<K, V> extends ConcurrentMap<K, V> {
   boolean isRecordingStats();
 
   /** Returns the {@link StatsCounter} used by this cache. */
-  @NonNull StatsCounter statsCounter();
+  StatsCounter statsCounter();
 
   /** Returns whether this cache notifies when an entry is removed. */
   boolean hasRemovalListener();
@@ -51,7 +50,7 @@ interface LocalCache<K, V> extends ConcurrentMap<K, V> {
   void notifyRemoval(@Nullable K key, @Nullable V value, RemovalCause cause);
 
   /** Returns the {@link Executor} used by this cache. */
-  @NonNull Executor executor();
+  Executor executor();
 
   /** Returns the map of in-flight refresh operations. */
   ConcurrentMap<Object, CompletableFuture<?>> refreshes();
@@ -63,10 +62,10 @@ interface LocalCache<K, V> extends ConcurrentMap<K, V> {
   @Nullable Expiry<K, V> expiry();
 
   /** Returns the {@link Ticker} used by this cache for expiration. */
-  @NonNull Ticker expirationTicker();
+  Ticker expirationTicker();
 
   /** Returns the {@link Ticker} used by this cache for statistics. */
-  @NonNull Ticker statsTicker();
+  Ticker statsTicker();
 
   /** See {@link Cache#estimatedSize()}. */
   long estimatedSize();
@@ -79,25 +78,24 @@ interface LocalCache<K, V> extends ConcurrentMap<K, V> {
    * to record the hit and miss statistics based on the success of this operation.
    */
   @Nullable
-  V getIfPresent(@NonNull K key, boolean recordStats);
+  V getIfPresent(K key, boolean recordStats);
 
   /**
    * See {@link Cache#getIfPresent(K)}. This method differs by not recording the access with
    * the statistics nor the eviction policy, and populates the write time if known.
    */
   @Nullable
-  V getIfPresentQuietly(@NonNull K key, @NonNull long[/* 1 */] writeTime);
+  V getIfPresentQuietly(K key, long[/* 1 */] writeTime);
 
   /** See {@link Cache#getAllPresent}. */
-  @NonNull
-  Map<K, V> getAllPresent(@NonNull Iterable<? extends K> keys);
+  Map<K, V> getAllPresent(Iterable<? extends K> keys);
 
   /**
    * See {@link Cache#put(Object, Object)}. This method differs by allowing the operation to not
    * notify the writer when an entry was inserted or updated.
    */
   @Nullable
-  V put(@NonNull K key, @NonNull V value, boolean notifyWriter);
+  V put(K key, V value, boolean notifyWriter);
 
   @Override
   default @Nullable V compute(K key,
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalManualCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalManualCache.java
index 3531408a0a..4e81348bc7 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalManualCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalManualCache.java
@@ -26,7 +26,6 @@
 import java.util.concurrent.ConcurrentMap;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.stats.CacheStats;
@@ -58,6 +57,7 @@ default void cleanUp() {
   }
 
   @Override
+  @SuppressWarnings("NullAway")
   default @Nullable V get(K key, Function<? super K, ? extends V> mappingFunction) {
     return cache().computeIfAbsent(key, mappingFunction);
   }
@@ -95,7 +95,7 @@ default Map<K, V> getAll(Iterable<? extends K> keys,
    * during the load are replaced when the loaded entries are inserted into the cache.
    */
   default void bulkLoad(Set<K> keysToLoad, Map<K, V> result,
-      Function<Set<? extends @NonNull K>, @NonNull Map<K, V>> mappingFunction) {
+      Function<Set<? extends K>, Map<K, V>> mappingFunction) {
     boolean success = false;
     long startTime = cache().statsTicker().read();
     try {
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java
index 9b9058e113..d0ef1759fd 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java
@@ -18,7 +18,6 @@
 import java.lang.ref.ReferenceQueue;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.AccessOrderDeque.AccessOrder;
@@ -42,7 +41,6 @@ abstract class Node<K, V> implements AccessOrder<Node<K, V>>, WriteOrder<Node<K,
    * Returns the reference that the cache is holding the entry by. This is either the key if
    * strongly held or a {@link java.lang.ref.WeakReference} to that key.
    */
-  @NonNull
   public abstract Object getKeyReference();
 
   /** Return the value or {@code null} if it has been reclaimed by the garbage collector. */
@@ -53,7 +51,6 @@ abstract class Node<K, V> implements AccessOrder<Node<K, V>>, WriteOrder<Node<K,
    * Returns the reference to the value. This is either the value if strongly held or a
    * {@link java.lang.ref.Reference} to that value.
    */
-  @NonNull
   public abstract Object getValueReference();
 
   /**
@@ -61,13 +58,13 @@ abstract class Node<K, V> implements AccessOrder<Node<K, V>>, WriteOrder<Node<K,
    * and rely on the memory fence when the lock is released.
    */
   @GuardedBy("this")
-  public abstract void setValue(@NonNull V value, @Nullable ReferenceQueue<V> referenceQueue);
+  public abstract void setValue(V value, @Nullable ReferenceQueue<V> referenceQueue);
 
   /**
    * Returns {@code true} if the given objects are considered equivalent. A strongly held value is
    * compared by equality and a weakly or softly held value is compared by identity.
    */
-  public abstract boolean containsValue(@NonNull Object value);
+  public abstract boolean containsValue(Object value);
 
   /** Returns the weight of this entry from the entry's perspective. */
   @NonNegative
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java
index d6e6bd6450..8db305e4a9 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java
@@ -23,7 +23,6 @@
 import java.util.concurrent.TimeUnit;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -54,7 +53,7 @@ public interface Policy<K, V> {
    * @throws NullPointerException if the specified key is null
    */
   @Nullable
-  V getIfPresentQuietly(@NonNull K key);
+  V getIfPresentQuietly(K key);
 
   /**
    * Returns access to perform operations based on the maximum size or maximum weight eviction
@@ -63,7 +62,6 @@ public interface Policy<K, V> {
    *
    * @return access to low-level operations for this cache if an eviction policy is used
    */
-  @NonNull
   Optional<Eviction<K, V>> eviction();
 
   /**
@@ -80,7 +78,6 @@ public interface Policy<K, V> {
    * @return access to low-level operations for this cache if a time-to-idle expiration policy is
    *         used
    */
-  @NonNull
   Optional<FixedExpiration<K, V>> expireAfterAccess();
 
   /**
@@ -94,7 +91,6 @@ public interface Policy<K, V> {
    * @return access to low-level operations for this cache if a time-to-live expiration policy is
    *         used
    */
-  @NonNull
   Optional<FixedExpiration<K, V>> expireAfterWrite();
 
   /**
@@ -107,7 +103,6 @@ public interface Policy<K, V> {
    *
    * @return access to low-level operations for this cache if a variable expiration policy is used
    */
-  @NonNull
   Optional<VarExpiration<K, V>> expireVariably();
 
   /**
@@ -120,7 +115,6 @@ public interface Policy<K, V> {
    *
    * @return access to low-level operations for this cache if a time-to-live refresh policy is used
    */
-  @NonNull
   Optional<FixedRefresh<K, V>> refreshAfterWrite();
 
   /** The low-level operations for a cache with a size-based eviction policy. */
@@ -140,8 +134,7 @@ interface Eviction<K, V> {
      * @param key the key for the entry being queried
      * @return the weight if the entry is present in the cache
      */
-    @NonNull
-    OptionalInt weightOf(@NonNull K key);
+    OptionalInt weightOf(K key);
 
     /**
      * Returns the approximate accumulated weight of entries in this cache. If this cache does not
@@ -149,7 +142,6 @@ interface Eviction<K, V> {
      *
      * @return the combined weight of the values in this cache
      */
-    @NonNull
     OptionalLong weightedSize();
 
     /**
@@ -190,8 +182,7 @@ interface Eviction<K, V> {
      *        the limit)
      * @return a snapshot view of the cache from coldest entry to the hottest
      */
-    @NonNull
-    Map<@NonNull K, @NonNull V> coldest(@NonNegative int limit);
+    Map<K, V> coldest(@NonNegative int limit);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -207,8 +198,7 @@ interface Eviction<K, V> {
      *        the limit)
      * @return a snapshot view of the cache from hottest entry to the coldest
      */
-    @NonNull
-    Map<@NonNull K, @NonNull V> hottest(@NonNegative int limit);
+    Map<K, V> hottest(@NonNegative int limit);
   }
 
   /** The low-level operations for a cache with a fixed expiration policy. */
@@ -228,8 +218,7 @@ interface FixedExpiration<K, V> {
      * @param unit the unit that {@code age} is expressed in
      * @return the age if the entry is present in the cache
      */
-    @NonNull
-    OptionalLong ageOf(@NonNull K key, @NonNull TimeUnit unit);
+    OptionalLong ageOf(K key, TimeUnit unit);
 
     /**
      * Returns the age of the entry based on the expiration policy. The entry's age is the cache's
@@ -242,8 +231,7 @@ interface FixedExpiration<K, V> {
      * @param key the key for the entry being queried
      * @return the age if the entry is present in the cache
      */
-    @NonNull
-    default Optional<Duration> ageOf(@NonNull K key) {
+    default Optional<Duration> ageOf(K key) {
       OptionalLong duration = ageOf(key, TimeUnit.NANOSECONDS);
       return duration.isPresent()
           ? Optional.of(Duration.ofNanos(duration.getAsLong()))
@@ -262,7 +250,7 @@ default Optional<Duration> ageOf(@NonNull K key) {
      * @return the length of time after which an entry should be automatically removed
      */
     @NonNegative
-    long getExpiresAfter(@NonNull TimeUnit unit);
+    long getExpiresAfter(TimeUnit unit);
 
     /**
      * Returns the fixed duration used to determine if an entry should be automatically removed due
@@ -272,7 +260,6 @@ default Optional<Duration> ageOf(@NonNull K key) {
      *
      * @return the length of time after which an entry should be automatically removed
      */
-    @NonNull
     default Duration getExpiresAfter() {
       return Duration.ofNanos(getExpiresAfter(TimeUnit.NANOSECONDS));
     }
@@ -287,7 +274,7 @@ default Duration getExpiresAfter() {
      * @param unit the unit that {@code duration} is expressed in
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    void setExpiresAfter(@NonNegative long duration, @NonNull TimeUnit unit);
+    void setExpiresAfter(@NonNegative long duration, TimeUnit unit);
 
     /**
      * Specifies that each entry should be automatically removed from the cache once a fixed
@@ -296,7 +283,7 @@ default Duration getExpiresAfter() {
      * @param duration the length of time after which an entry should be automatically removed
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    default void setExpiresAfter(@NonNull Duration duration) {
+    default void setExpiresAfter(Duration duration) {
       setExpiresAfter(duration.toNanos(), TimeUnit.NANOSECONDS);
     }
 
@@ -314,8 +301,7 @@ default void setExpiresAfter(@NonNull Duration duration) {
      *        the limit)
      * @return a snapshot view of the cache from oldest entry to the youngest
      */
-    @NonNull
-    Map<@NonNull K, @NonNull V> oldest(@NonNegative int limit);
+    Map<K, V> oldest(@NonNegative int limit);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -331,8 +317,7 @@ default void setExpiresAfter(@NonNull Duration duration) {
      *        the limit)
      * @return a snapshot view of the cache from youngest entry to the oldest
      */
-    @NonNull
-    Map<@NonNull K, @NonNull V> youngest(@NonNegative int limit);
+    Map<K, V> youngest(@NonNegative int limit);
   }
 
   /** The low-level operations for a cache with a variable expiration policy. */
@@ -348,8 +333,7 @@ interface VarExpiration<K, V> {
      * @param unit the unit that {@code age} is expressed in
      * @return the duration if the entry is present in the cache
      */
-    @NonNull
-    OptionalLong getExpiresAfter(@NonNull K key, @NonNull TimeUnit unit);
+    OptionalLong getExpiresAfter(K key, TimeUnit unit);
 
     /**
      * Returns the duration until the entry should be automatically removed. The expiration policy
@@ -358,8 +342,7 @@ interface VarExpiration<K, V> {
      * @param key the key for the entry being queried
      * @return the duration if the entry is present in the cache
      */
-    @NonNull
-    default Optional<Duration> getExpiresAfter(@NonNull K key) {
+    default Optional<Duration> getExpiresAfter(K key) {
       OptionalLong duration = getExpiresAfter(key, TimeUnit.NANOSECONDS);
       return duration.isPresent()
           ? Optional.of(Duration.ofNanos(duration.getAsLong()))
@@ -376,7 +359,7 @@ default Optional<Duration> getExpiresAfter(@NonNull K key) {
      * @throws IllegalArgumentException if {@code duration} is negative
      * @throws NullPointerException if the unit is null
      */
-    void setExpiresAfter(@NonNull K key, @NonNegative long duration, @NonNull TimeUnit unit);
+    void setExpiresAfter(K key, @NonNegative long duration, TimeUnit unit);
 
     /**
      * Specifies that the entry should be automatically removed from the cache once the duration has
@@ -386,7 +369,7 @@ default Optional<Duration> getExpiresAfter(@NonNull K key) {
      * @param duration the length of time from now when the entry should be automatically removed
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
+    default void setExpiresAfter(K key, Duration duration) {
       setExpiresAfter(key, duration.toNanos(), TimeUnit.NANOSECONDS);
     }
 
@@ -406,8 +389,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      *         mapping for the key.
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    @Nullable V putIfAbsent(@NonNull K key, @NonNull V value,
-        @NonNegative long duration, @NonNull TimeUnit unit);
+    @Nullable V putIfAbsent(K key, V value, @NonNegative long duration, TimeUnit unit);
 
     /**
      * Associates the {@code value} with the {@code key} in this cache if the specified key is not
@@ -422,7 +404,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      *         mapping for the key.
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    default @Nullable V putIfAbsent(@NonNull K key, @NonNull V value, @NonNull Duration duration) {
+    default @Nullable V putIfAbsent(K key, V value, Duration duration) {
       return putIfAbsent(key, value, duration.toNanos(), TimeUnit.NANOSECONDS);
     }
 
@@ -443,8 +425,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      * @throws IllegalArgumentException if {@code duration} is negative
      * @throws NullPointerException if the specified key or value is null
      */
-    @Nullable V put(@NonNull K key, @NonNull V value,
-        @NonNegative long duration, @NonNull TimeUnit unit);
+    @Nullable V put(K key, V value, @NonNegative long duration, TimeUnit unit);
 
     /**
      * Associates the {@code value} with the {@code key} in this cache. If the cache previously
@@ -460,7 +441,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      * @throws IllegalArgumentException if {@code duration} is negative
      * @throws NullPointerException if the specified key or value is null
      */
-    default @Nullable V put(@NonNull K key, @NonNull V value, @NonNull Duration duration) {
+    default @Nullable V put(K key, V value, Duration duration) {
       return put(key, value, duration.toNanos(), TimeUnit.NANOSECONDS);
     }
 
@@ -478,8 +459,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      *        the limit)
      * @return a snapshot view of the cache from oldest entry to the youngest
      */
-    @NonNull
-    Map<@NonNull K, @NonNull V> oldest(@NonNegative int limit);
+    Map<K, V> oldest(@NonNegative int limit);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -495,8 +475,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      *        the limit)
      * @return a snapshot view of the cache from youngest entry to the oldest
      */
-    @NonNull
-    Map<@NonNull K, @NonNull V> youngest(@NonNegative int limit);
+    Map<K, V> youngest(@NonNegative int limit);
   }
 
   /** The low-level operations for a cache with a fixed refresh policy. */
@@ -516,8 +495,7 @@ interface FixedRefresh<K, V> {
      * @param unit the unit that {@code age} is expressed in
      * @return the age if the entry is present in the cache
      */
-    @NonNull
-    OptionalLong ageOf(@NonNull K key, @NonNull TimeUnit unit);
+    OptionalLong ageOf(K key, TimeUnit unit);
 
     /**
      * Returns the age of the entry based on the expiration policy. The entry's age is the cache's
@@ -530,8 +508,7 @@ interface FixedRefresh<K, V> {
      * @param key the key for the entry being queried
      * @return the age if the entry is present in the cache
      */
-    @NonNull
-    default Optional<Duration> ageOf(@NonNull K key) {
+    default Optional<Duration> ageOf(K key) {
       OptionalLong duration = ageOf(key, TimeUnit.NANOSECONDS);
       return duration.isPresent()
           ? Optional.of(Duration.ofNanos(duration.getAsLong()))
@@ -550,7 +527,7 @@ default Optional<Duration> ageOf(@NonNull K key) {
      * @return the length of time after which an entry is eligible to be reloaded
      */
     @NonNegative
-    long getRefreshesAfter(@NonNull TimeUnit unit);
+    long getRefreshesAfter(TimeUnit unit);
 
     /**
      * Returns the fixed duration used to determine if an entry should be eligible for reloading due
@@ -560,7 +537,6 @@ default Optional<Duration> ageOf(@NonNull K key) {
      *
      * @return the length of time after which an entry is eligible to be reloaded
      */
-    @NonNull
     default Duration getRefreshesAfter() {
       return Duration.ofNanos(getRefreshesAfter(TimeUnit.NANOSECONDS));
     }
@@ -575,7 +551,7 @@ default Duration getRefreshesAfter() {
      * @param unit the unit that {@code duration} is expressed in
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    void setRefreshesAfter(@NonNegative long duration, @NonNull TimeUnit unit);
+    void setRefreshesAfter(@NonNegative long duration, TimeUnit unit);
 
     /**
      * Specifies that each entry should be eligible for reloading once a fixed duration has elapsed.
@@ -584,7 +560,7 @@ default Duration getRefreshesAfter() {
      * @param duration the length of time after which an entry is eligible to be reloaded
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    default void setRefreshesAfter(@NonNull Duration duration) {
+    default void setRefreshesAfter(Duration duration) {
       setRefreshesAfter(duration.toNanos(), TimeUnit.NANOSECONDS);
     }
   }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/References.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/References.java
index 95f568a189..717101e48d 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/References.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/References.java
@@ -21,7 +21,6 @@
 import java.lang.ref.SoftReference;
 import java.lang.ref.WeakReference;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -54,7 +53,6 @@ interface InternalReference<E> {
      *
      * @return the key that is associated to the cached entry
      */
-    @NonNull
     Object getKeyReference();
 
     /**
@@ -84,7 +82,7 @@ static final class LookupKeyReference<E> implements InternalReference<E> {
     private final int hashCode;
     private final E e;
 
-    public LookupKeyReference(@NonNull E e) {
+    public LookupKeyReference(E e) {
       this.hashCode = System.identityHashCode(e);
       this.e = requireNonNull(e);
     }
@@ -148,7 +146,7 @@ static final class WeakValueReference<V> extends WeakReference<V>
       implements InternalReference<V> {
     private final Object keyReference;
 
-    public WeakValueReference(@NonNull Object keyReference,
+    public WeakValueReference(Object keyReference,
         @Nullable V value, @Nullable ReferenceQueue<V> queue) {
       super(value, queue);
       this.keyReference = keyReference;
@@ -180,7 +178,7 @@ static final class SoftValueReference<V> extends SoftReference<V>
       implements InternalReference<V> {
     private final Object keyReference;
 
-    public SoftValueReference(@NonNull Object keyReference,
+    public SoftValueReference(Object keyReference,
         @Nullable V value, @Nullable ReferenceQueue<V> queue) {
       super(value, queue);
       this.keyReference = keyReference;
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/RemovalListener.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/RemovalListener.java
index fd84bbd50c..963e6b2a5e 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/RemovalListener.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/RemovalListener.java
@@ -15,7 +15,6 @@
  */
 package com.github.benmanes.caffeine.cache;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -46,5 +45,5 @@ public interface RemovalListener<K, V> {
    * @param value the value represented by this entry, or {@code null} if collected
    * @param cause the reason for which the entry was removed
    */
-  void onRemoval(@Nullable K key, @Nullable V value, @NonNull RemovalCause cause);
+  void onRemoval(@Nullable K key, @Nullable V value, RemovalCause cause);
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Scheduler.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Scheduler.java
index 091ad0e804..a3454c1679 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Scheduler.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Scheduler.java
@@ -28,9 +28,6 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
-import org.checkerframework.checker.index.qual.Positive;
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * A scheduler that submits a task to an executor after a given delay.
  *
@@ -48,15 +45,14 @@ public interface Scheduler {
    * @param unit a {@code TimeUnit} determining how to interpret the {@code delay} parameter
    * @return a scheduled future representing pending submission of the task
    */
-  @NonNull Future<?> schedule(@NonNull Executor executor,
-      @NonNull Runnable command, @Positive long delay, @NonNull TimeUnit unit);
+  Future<?> schedule(Executor executor, Runnable command, long delay, TimeUnit unit);
 
   /**
    * Returns a scheduler that always returns a successfully completed future.
    *
    * @return a scheduler that always returns a successfully completed future
    */
-  static @NonNull Scheduler disabledScheduler() {
+  static Scheduler disabledScheduler() {
     return DisabledScheduler.INSTANCE;
   }
 
@@ -66,7 +62,7 @@ public interface Scheduler {
    *
    * @return a scheduler that uses the system-wide scheduling thread
    */
-  static @NonNull Scheduler systemScheduler() {
+  static Scheduler systemScheduler() {
     return SystemScheduler.INSTANCE;
   }
 
@@ -76,8 +72,7 @@ public interface Scheduler {
    * @param scheduledExecutorService the executor to schedule on
    * @return a scheduler that delegates to the a {@link ScheduledExecutorService}
    */
-  static @NonNull Scheduler forScheduledExecutorService(
-      @NonNull ScheduledExecutorService scheduledExecutorService) {
+  static Scheduler forScheduledExecutorService(ScheduledExecutorService scheduledExecutorService) {
     return new ExecutorServiceScheduler(scheduledExecutorService);
   }
 
@@ -88,7 +83,7 @@ public interface Scheduler {
    * @param scheduler the scheduler to delegate to
    * @return an scheduler that suppresses and logs any exception thrown by the delegate
    */
-  static @NonNull Scheduler guardedScheduler(@NonNull Scheduler scheduler) {
+  static Scheduler guardedScheduler(Scheduler scheduler) {
     return (scheduler instanceof GuardedScheduler) ? scheduler : new GuardedScheduler(scheduler);
   }
 }
@@ -144,8 +139,7 @@ final class GuardedScheduler implements Scheduler, Serializable {
   }
 
   @Override
-  public @NonNull Future<?> schedule(@NonNull Executor executor,
-      @NonNull Runnable command, long delay, @NonNull TimeUnit unit) {
+  public Future<?> schedule(Executor executor, Runnable command, long delay, TimeUnit unit) {
     try {
       Future<?> future = delegate.schedule(executor, command, delay, unit);
       return (future == null) ? DisabledFuture.INSTANCE : future;
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Ticker.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Ticker.java
index 8df2bcedd9..3ec78cdc8d 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Ticker.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Ticker.java
@@ -15,8 +15,6 @@
  */
 package com.github.benmanes.caffeine.cache;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * A time source that returns a time value representing the number of nanoseconds elapsed since some
  * fixed but arbitrary point in time.
@@ -37,7 +35,7 @@ public interface Ticker {
    *
    * @return a ticker that reads the current time using {@link System#nanoTime}
    */
-  static @NonNull Ticker systemTicker() {
+  static Ticker systemTicker() {
     return SystemTicker.INSTANCE;
   }
 
@@ -46,7 +44,7 @@ public interface Ticker {
    *
    * @return a ticker that always returns {@code 0}
    */
-  static @NonNull Ticker disabledTicker() {
+  static Ticker disabledTicker() {
     return DisabledTicker.INSTANCE;
   }
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java
index 105826b596..884e261a34 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java
@@ -29,7 +29,6 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -167,7 +166,7 @@ void expire(int index, long previousTicks, long currentTicks) {
    *
    * @param node the entry in the cache
    */
-  public void schedule(@NonNull Node<K, V> node) {
+  public void schedule(Node<K, V> node) {
     Node<K, V> sentinel = findBucket(node.getVariableTime());
     link(sentinel, node);
   }
@@ -177,7 +176,7 @@ public void schedule(@NonNull Node<K, V> node) {
    *
    * @param node the entry in the cache
    */
-  public void reschedule(@NonNull Node<K, V> node) {
+  public void reschedule(Node<K, V> node) {
     if (node.getNextInVariableOrder() != null) {
       unlink(node);
       schedule(node);
@@ -189,7 +188,7 @@ public void reschedule(@NonNull Node<K, V> node) {
    *
    * @param node the entry in the cache
    */
-  public void deschedule(@NonNull Node<K, V> node) {
+  public void deschedule(Node<K, V> node) {
     unlink(node);
     node.setNextInVariableOrder(null);
     node.setPreviousInVariableOrder(null);
@@ -290,7 +289,7 @@ long peekAhead(int i) {
    * @param transformer a function that unwraps the value
    * @return an unmodifiable snapshot in the desired order
    */
-  public Map<K, V> snapshot(boolean ascending, int limit, @NonNull Function<V, V> transformer) {
+  public Map<K, V> snapshot(boolean ascending, int limit, Function<V, V> transformer) {
     requireArgument(limit >= 0);
 
     Map<K, V> map = new LinkedHashMap<>(Math.min(limit, cache.size()));
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java
index 030ed96982..3901e92622 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java
@@ -20,7 +20,6 @@
 import java.io.Serializable;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * Calculates the weights of cache entries. The total weight threshold is used to determine when an
@@ -42,7 +41,7 @@ public interface Weigher<K, V> {
    * @return the weight of the entry; must be non-negative
    */
   @NonNegative
-  int weigh(@NonNull K key, @NonNull V value);
+  int weigh(K key, V value);
 
   /**
    * Returns a weigher where an entry has a weight of {@code 1}.
@@ -51,7 +50,6 @@ public interface Weigher<K, V> {
    * @param <V> the type of values
    * @return a weigher where an entry has a weight of {@code 1}
    */
-  @NonNull
   static <K, V> Weigher<K, V> singletonWeigher() {
     @SuppressWarnings("unchecked")
     Weigher<K, V> self = (Weigher<K, V>) SingletonWeigher.INSTANCE;
@@ -66,8 +64,7 @@ static <K, V> Weigher<K, V> singletonWeigher() {
    * @param <V> the type of values
    * @return a weigher that enforces that the weight is non-negative
    */
-  @NonNull
-  static <K, V> Weigher<K, V> boundedWeigher(@NonNull Weigher<K, V> delegate) {
+  static <K, V> Weigher<K, V> boundedWeigher(Weigher<K, V> delegate) {
     return new BoundedWeigher<>(delegate);
   }
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/package-info.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/package-info.java
index ff5166bb15..5ffa24718b 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/package-info.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/package-info.java
@@ -30,4 +30,11 @@
  *
  * @author ben.manes@gmail.com (Ben Manes)
  */
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.FIELD)
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.PARAMETER)
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.RETURN)
 package com.github.benmanes.caffeine.cache;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+import org.checkerframework.framework.qual.TypeUseLocation;
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java
index 11a3d20c3c..a0a5d937f4 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java
@@ -18,7 +18,6 @@
 import java.util.Objects;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.LoadingCache;
@@ -115,7 +114,6 @@ public static CacheStats of(@NonNegative long hitCount, @NonNegative long missCo
    *
    * @return an empty statistics instance
    */
-  @NonNull
   public static CacheStats empty() {
     return EMPTY_STATS;
   }
@@ -308,8 +306,7 @@ public long evictionWeight() {
    * @param other the statistics to subtract with
    * @return the difference between this instance and {@code other}
    */
-  @NonNull
-  public CacheStats minus(@NonNull CacheStats other) {
+  public CacheStats minus(CacheStats other) {
     return CacheStats.of(
         Math.max(0L, saturatedSubtract(hitCount, other.hitCount)),
         Math.max(0L, saturatedSubtract(missCount, other.missCount)),
@@ -331,8 +328,7 @@ public CacheStats minus(@NonNull CacheStats other) {
    * @param other the statistics to add with
    * @return the sum of the statistics
    */
-  @NonNull
-  public CacheStats plus(@NonNull CacheStats other) {
+  public CacheStats plus(CacheStats other) {
     return CacheStats.of(
         saturatedAdd(hitCount, other.hitCount),
         saturatedAdd(missCount, other.missCount),
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/ConcurrentStatsCounter.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/ConcurrentStatsCounter.java
index 9b2633d42d..1428ac62aa 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/ConcurrentStatsCounter.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/ConcurrentStatsCounter.java
@@ -17,8 +17,6 @@
 
 import java.util.concurrent.atomic.LongAdder;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.RemovalCause;
 
@@ -99,7 +97,7 @@ private static long negativeToMaxValue(long value) {
    *
    * @param other the counter to increment from
    */
-  public void incrementBy(@NonNull StatsCounter other) {
+  public void incrementBy(StatsCounter other) {
     CacheStats otherStats = other.snapshot();
     hitCount.add(otherStats.hitCount());
     missCount.add(otherStats.missCount());
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java
index 108bbc2dd1..6b234d903d 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java
@@ -18,7 +18,6 @@
 import java.util.Map;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.RemovalCause;
@@ -91,7 +90,6 @@ public interface StatsCounter {
    *
    * @return a snapshot of this counter's values
    */
-  @NonNull
   CacheStats snapshot();
 
   /**
@@ -99,7 +97,7 @@ public interface StatsCounter {
    *
    * @return an accumulator that does not record metrics
    */
-  static @NonNull StatsCounter disabledStatsCounter() {
+  static StatsCounter disabledStatsCounter() {
     return DisabledStatsCounter.INSTANCE;
   }
 
@@ -110,7 +108,7 @@ public interface StatsCounter {
    * @param statsCounter the accumulator to delegate to
    * @return an accumulator that suppresses and logs any exception thrown by the delegate
    */
-  static @NonNull StatsCounter guardedStatsCounter(@NonNull StatsCounter statsCounter) {
+  static StatsCounter guardedStatsCounter(StatsCounter statsCounter) {
     return (statsCounter instanceof GuardedStatsCounter)
         ? statsCounter
         : new GuardedStatsCounter(statsCounter);
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/package-info.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/package-info.java
index 03acbe016c..49c6a4bf59 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/package-info.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/package-info.java
@@ -19,4 +19,11 @@
  *
  * @author ben.manes@gmail.com (Ben Manes)
  */
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.FIELD)
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.PARAMETER)
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.RETURN)
 package com.github.benmanes.caffeine.cache.stats;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+import org.checkerframework.framework.qual.TypeUseLocation;
diff --git a/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/GuavaCacheFromContext.java b/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/GuavaCacheFromContext.java
index b774f262d9..951d1cf0d3 100644
--- a/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/GuavaCacheFromContext.java
+++ b/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/GuavaCacheFromContext.java
@@ -35,8 +35,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.LoadingCache;
 import com.github.benmanes.caffeine.cache.Policy;
@@ -435,7 +433,7 @@ public Policy<K, V> policy() {
         @Override public boolean isRecordingStats() {
           return isRecordingStats;
         }
-        @Override public V getIfPresentQuietly(@NonNull Object key) {
+        @Override public V getIfPresentQuietly(K key) {
           return cache.asMap().get(key);
         }
         @Override public Optional<Eviction<K, V>> eviction() {
diff --git a/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/RemovalNotification.java b/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/RemovalNotification.java
index f4c05838fc..c93aee09d6 100644
--- a/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/RemovalNotification.java
+++ b/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/RemovalNotification.java
@@ -19,7 +19,6 @@
 
 import java.util.AbstractMap.SimpleImmutableEntry;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.RemovalCause;
@@ -45,7 +44,7 @@ public final class RemovalNotification<K, V> extends SimpleImmutableEntry<K, V>
    * @param value the value represented by this entry
    * @param cause the reason for which the entry was removed
    */
-  public RemovalNotification(@Nullable K key, @Nullable V value, @NonNull RemovalCause cause) {
+  public RemovalNotification(@Nullable K key, @Nullable V value, RemovalCause cause) {
     super(key, value);
     this.cause = requireNonNull(cause);
   }
@@ -53,7 +52,6 @@ public RemovalNotification(@Nullable K key, @Nullable V value, @NonNull RemovalC
   /**
    * @return the cause for which the entry was removed
    */
-  @NonNull
   public RemovalCause getCause() {
     return cause;
   }
diff --git a/examples/coalescing-bulkloader/src/main/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloader.java b/examples/coalescing-bulkloader/src/main/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloader.java
index 5c2087e89b..5c3b1a8dbd 100644
--- a/examples/coalescing-bulkloader/src/main/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloader.java
+++ b/examples/coalescing-bulkloader/src/main/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloader.java
@@ -36,7 +36,6 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.stream.Stream;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * An implementation of {@link AsyncCacheLoader} that delays fetching a bit until "enough" keys are collected
@@ -141,7 +140,7 @@ private CoalescingBulkloader(int maxLoadSize, long maxDelay, Consumer<Collection
         this.maxDelay = maxDelay;
     }
 
-    @Override public @NonNull CompletableFuture<Value> asyncLoad(@NonNull Key key, @NonNull Executor executor) {
+    @Override public CompletableFuture<Value> asyncLoad(Key key, Executor executor) {
         final WaitingKey waitingKey = new WaitingKey();
         waitingKey.key = key;
         waitingKey.future = new CompletableFuture<>();
diff --git a/examples/coalescing-bulkloader/src/test/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloaderTest.java b/examples/coalescing-bulkloader/src/test/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloaderTest.java
index 8d00f5de81..9653c30023 100644
--- a/examples/coalescing-bulkloader/src/test/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloaderTest.java
+++ b/examples/coalescing-bulkloader/src/test/java/com/github/benmanes/caffeine/examples/coalescing/bulkloader/CoalescingBulkloaderTest.java
@@ -35,7 +35,6 @@
 import java.util.function.Function;
 import java.util.stream.Stream;
 import org.awaitility.Awaitility;
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TestRule;
@@ -71,7 +70,7 @@ public static List<Function<Function<Stream<Integer>, Stream<Integer>>, Coalesci
         );
     }
 
-    @NonNull private AsyncLoadingCache<Integer, Integer> createCache(AtomicInteger loaderCalled) {
+    private AsyncLoadingCache<Integer, Integer> createCache(AtomicInteger loaderCalled) {
         return Caffeine.newBuilder().buildAsync(cbl.apply(ints -> {
             loaderCalled.incrementAndGet();
             try {
diff --git a/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuava.java b/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuava.java
index 4a23fc2904..83bbd579b9 100644
--- a/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuava.java
+++ b/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuava.java
@@ -17,8 +17,6 @@
 
 import java.lang.reflect.Method;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 import com.github.benmanes.caffeine.cache.Caffeine;
 import com.github.benmanes.caffeine.guava.CaffeinatedGuavaLoadingCache.BulkLoader;
 import com.github.benmanes.caffeine.guava.CaffeinatedGuavaLoadingCache.SingleLoader;
@@ -41,9 +39,7 @@ private CaffeinatedGuava() {}
    * @param builder the configured cache builder
    * @return a cache exposed under the Guava APIs
    */
-  @NonNull
-  public static <K, V, K1 extends K, V1 extends V> Cache<K1, V1> build(
-      @NonNull Caffeine<K, V> builder) {
+  public static <K, V, K1 extends K, V1 extends V> Cache<K1, V1> build(Caffeine<K, V> builder) {
     return new CaffeinatedGuavaCache<>(builder.build());
   }
 
@@ -54,9 +50,8 @@ public static <K, V, K1 extends K, V1 extends V> Cache<K1, V1> build(
    * @param loader the cache loader used to obtain new values
    * @return a cache exposed under the Guava APIs
    */
-  @NonNull
   public static <K, V, K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
-      @NonNull Caffeine<K, V> builder, @NonNull CacheLoader<? super K1, V1> loader) {
+      Caffeine<K, V> builder, CacheLoader<? super K1, V1> loader) {
     @SuppressWarnings("unchecked")
     CacheLoader<K1, V1> castedLoader = (CacheLoader<K1, V1>) loader;
     return build(builder, hasLoadAll(castedLoader)
@@ -71,10 +66,9 @@ public static <K, V, K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
    * @param loader the cache loader used to obtain new values
    * @return a cache exposed under the Guava APIs
    */
-  @NonNull
   public static <K, V, K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
-      @NonNull Caffeine<K, V> builder,
-      com.github.benmanes.caffeine.cache.@NonNull CacheLoader<? super K1, V1> loader) {
+      Caffeine<K, V> builder,
+      com.github.benmanes.caffeine.cache.CacheLoader<? super K1, V1> loader) {
     return new CaffeinatedGuavaLoadingCache<>(builder.build(loader));
   }
 
diff --git a/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuavaLoadingCache.java b/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuavaLoadingCache.java
index 927ef40d02..43f0ab8300 100644
--- a/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuavaLoadingCache.java
+++ b/guava/src/main/java/com/github/benmanes/caffeine/guava/CaffeinatedGuavaLoadingCache.java
@@ -23,8 +23,6 @@
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 import com.github.benmanes.caffeine.cache.CacheLoader;
 import com.google.common.base.Throwables;
 import com.google.common.cache.CacheLoader.InvalidCacheLoadException;
@@ -113,7 +111,7 @@ public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionExc
 
   @Override
   @SuppressWarnings("NullAway")
-  public V apply(@NonNull K key) {
+  public V apply(K key) {
     return cache.get(key);
   }
 
diff --git a/guava/src/main/java/com/github/benmanes/caffeine/guava/package-info.java b/guava/src/main/java/com/github/benmanes/caffeine/guava/package-info.java
new file mode 100644
index 0000000000..cac388c5aa
--- /dev/null
+++ b/guava/src/main/java/com/github/benmanes/caffeine/guava/package-info.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2021 Ben Manes. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * This package contains an adapter to the Guava cache interfaces.
+ *
+ * @author ben.manes@gmail.com (Ben Manes)
+ */
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.FIELD)
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.PARAMETER)
+@DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.RETURN)
+package com.github.benmanes.caffeine.guava;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+import org.checkerframework.framework.qual.TypeUseLocation;
diff --git a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/CacheProxy.java b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/CacheProxy.java
index 27de5ca04e..ceebcca7ae 100644
--- a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/CacheProxy.java
+++ b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/CacheProxy.java
@@ -53,7 +53,6 @@
 import javax.cache.processor.EntryProcessorException;
 import javax.cache.processor.EntryProcessorResult;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.Ticker;
@@ -1064,7 +1063,7 @@ protected final void requireNotClosed() {
    * @return a copy of the object if storing by value or the same instance if by reference
    */
   @SuppressWarnings("NullAway")
-  protected final @NonNull <T> T copyOf(@Nullable T object) {
+  protected final <T> T copyOf(@Nullable T object) {
     if (object == null) {
       return null;
     }
diff --git a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/configuration/FactoryCreator.java b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/configuration/FactoryCreator.java
index fae6789732..bab337d86c 100644
--- a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/configuration/FactoryCreator.java
+++ b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/configuration/FactoryCreator.java
@@ -15,7 +15,6 @@
  */
 package com.github.benmanes.caffeine.jcache.configuration;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import javax.cache.configuration.Factory;
 
 /**
@@ -33,6 +32,5 @@ public interface FactoryCreator {
    * @param <T> the type of the instances being produced
    * @return a {@link Factory} for the specified class
    */
-  @NonNull
   <T> Factory<T> factoryOf(String className);
 }
diff --git a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/copy/Copier.java b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/copy/Copier.java
index 0f81ea4c14..658f14e726 100644
--- a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/copy/Copier.java
+++ b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/copy/Copier.java
@@ -15,8 +15,6 @@
  */
 package com.github.benmanes.caffeine.jcache.copy;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * An object is copied when the cache is configured with <tt>storeByValue</tt> to guard against
  * mutations of the key or value.
@@ -34,8 +32,7 @@ public interface Copier {
    * @param <T> the type of object being copied
    * @return a copy of the object
    */
-  @NonNull
-  <T> T copy(@NonNull T object, @NonNull ClassLoader classLoader);
+  <T> T copy(T object, ClassLoader classLoader);
 
   /** @return a copy strategy that performs an identity function, for use by store-by-reference */
   static Copier identity() {
@@ -47,7 +44,7 @@ enum IdentityCopier implements Copier {
   INSTANCE;
 
   @Override
-  public <T> T copy(@NonNull T object, @NonNull ClassLoader classLoader) {
+  public <T> T copy(T object, ClassLoader classLoader) {
     return object;
   }
 }
diff --git a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/event/EventTypeAwareListener.java b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/event/EventTypeAwareListener.java
index 3f74937023..9431e0cd48 100644
--- a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/event/EventTypeAwareListener.java
+++ b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/event/EventTypeAwareListener.java
@@ -22,7 +22,6 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import javax.cache.event.CacheEntryCreatedListener;
 import javax.cache.event.CacheEntryEvent;
 import javax.cache.event.CacheEntryExpiredListener;
@@ -49,7 +48,7 @@ public EventTypeAwareListener(CacheEntryListener<? super K, ? super V> listener)
 
   /** Returns if the backing listener consumes this type of event. */
   @SuppressWarnings("PMD.SwitchStmtsShouldHaveDefault")
-  public boolean isCompatible(@NonNull EventType eventType) {
+  public boolean isCompatible(EventType eventType) {
     switch (eventType) {
       case CREATED:
         return (listener instanceof CacheEntryCreatedListener<?, ?>);
@@ -65,7 +64,7 @@ public boolean isCompatible(@NonNull EventType eventType) {
 
   /** Processes the event and logs if an exception is thrown. */
   @SuppressWarnings("PMD.SwitchStmtsShouldHaveDefault")
-  public void dispatch(@NonNull JCacheEntryEvent<K, V> event) {
+  public void dispatch(JCacheEntryEvent<K, V> event) {
     try {
       if (event.getSource().isClosed()) {
         return;
diff --git a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/expiry/JCacheExpiryPolicy.java b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/expiry/JCacheExpiryPolicy.java
index d334692598..78f7369c36 100644
--- a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/expiry/JCacheExpiryPolicy.java
+++ b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/expiry/JCacheExpiryPolicy.java
@@ -20,11 +20,11 @@
 import java.io.Serializable;
 import java.util.Objects;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-import org.checkerframework.checker.nullness.qual.Nullable;
 import javax.cache.expiry.Duration;
 import javax.cache.expiry.ExpiryPolicy;
 
+import org.checkerframework.checker.nullness.qual.Nullable;
+
 /**
  * A customized expiration policy.
  *
@@ -37,7 +37,7 @@ public final class JCacheExpiryPolicy implements ExpiryPolicy, Serializable {
   private final @Nullable Duration update;
   private final @Nullable Duration access;
 
-  public JCacheExpiryPolicy(@NonNull Duration creation,
+  public JCacheExpiryPolicy(Duration creation,
       @Nullable Duration update, @Nullable Duration access) {
     this.creation = requireNonNull(creation);
     this.update = update;