diff --git a/crossbeam-channel/examples/fibonacci.rs b/crossbeam-channel/examples/fibonacci.rs
index cf22b7a57..e6f5e89c0 100644
--- a/crossbeam-channel/examples/fibonacci.rs
+++ b/crossbeam-channel/examples/fibonacci.rs
@@ -10,7 +10,7 @@ fn fibonacci(sender: Sender<u64>) {
     while sender.send(x).is_ok() {
         let tmp = x;
         x = y;
-        y = tmp + y;
+        y += tmp;
     }
 }
 
diff --git a/crossbeam-channel/examples/stopwatch.rs b/crossbeam-channel/examples/stopwatch.rs
index 98895c5a3..3a7578e00 100644
--- a/crossbeam-channel/examples/stopwatch.rs
+++ b/crossbeam-channel/examples/stopwatch.rs
@@ -33,11 +33,7 @@ fn main() {
 
     // Prints the elapsed time.
     fn show(dur: Duration) {
-        println!(
-            "Elapsed: {}.{:03} sec",
-            dur.as_secs(),
-            dur.subsec_nanos() / 1_000_000
-        );
+        println!("Elapsed: {}.{:03} sec", dur.as_secs(), dur.subsec_millis());
     }
 
     let start = Instant::now();
diff --git a/crossbeam-channel/tests/golang.rs b/crossbeam-channel/tests/golang.rs
index cd7001326..afd07baf9 100644
--- a/crossbeam-channel/tests/golang.rs
+++ b/crossbeam-channel/tests/golang.rs
@@ -176,7 +176,7 @@ unsafe impl GlobalAlloc for Counter {
         if !ret.is_null() {
             ALLOCATED.fetch_add(layout.size(), SeqCst);
         }
-        return ret;
+        ret
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
diff --git a/crossbeam-deque/tests/fifo.rs b/crossbeam-deque/tests/fifo.rs
index f86fbd1b8..e2365fb91 100644
--- a/crossbeam-deque/tests/fifo.rs
+++ b/crossbeam-deque/tests/fifo.rs
@@ -167,7 +167,7 @@ fn stress() {
                         hits.fetch_add(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         hits.fetch_add(1, SeqCst);
                     }
                 }
@@ -178,7 +178,7 @@ fn stress() {
         let mut expected = 0;
         while expected < COUNT {
             if rng.gen_range(0..3) == 0 {
-                while let Some(_) = w.pop() {
+                while w.pop().is_some() {
                     hits.fetch_add(1, SeqCst);
                 }
             } else {
@@ -188,7 +188,7 @@ fn stress() {
         }
 
         while hits.load(SeqCst) < COUNT {
-            while let Some(_) = w.pop() {
+            while w.pop().is_some() {
                 hits.fetch_add(1, SeqCst);
             }
         }
@@ -227,7 +227,7 @@ fn no_starvation() {
                         hits.fetch_add(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         hits.fetch_add(1, SeqCst);
                     }
                 }
@@ -239,7 +239,7 @@ fn no_starvation() {
         loop {
             for i in 0..rng.gen_range(0..COUNT) {
                 if rng.gen_range(0..3) == 0 && my_hits == 0 {
-                    while let Some(_) = w.pop() {
+                    while w.pop().is_some() {
                         my_hits += 1;
                     }
                 } else {
@@ -300,7 +300,7 @@ fn destructors() {
                         remaining.fetch_sub(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         cnt += 1;
                         remaining.fetch_sub(1, SeqCst);
                     }
@@ -309,7 +309,7 @@ fn destructors() {
         }
 
         for _ in 0..STEPS {
-            if let Some(_) = w.pop() {
+            if w.pop().is_some() {
                 remaining.fetch_sub(1, SeqCst);
             }
         }
diff --git a/crossbeam-deque/tests/injector.rs b/crossbeam-deque/tests/injector.rs
index fb2298340..3f74d1bfb 100644
--- a/crossbeam-deque/tests/injector.rs
+++ b/crossbeam-deque/tests/injector.rs
@@ -178,7 +178,7 @@ fn stress() {
                         hits.fetch_add(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         hits.fetch_add(1, SeqCst);
                     }
                 }
@@ -238,7 +238,7 @@ fn no_starvation() {
                         hits.fetch_add(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         hits.fetch_add(1, SeqCst);
                     }
                 }
@@ -311,7 +311,7 @@ fn destructors() {
                         remaining.fetch_sub(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         cnt += 1;
                         remaining.fetch_sub(1, SeqCst);
                     }
diff --git a/crossbeam-deque/tests/lifo.rs b/crossbeam-deque/tests/lifo.rs
index 8681db0dc..3e99e95c5 100644
--- a/crossbeam-deque/tests/lifo.rs
+++ b/crossbeam-deque/tests/lifo.rs
@@ -167,7 +167,7 @@ fn stress() {
                         hits.fetch_add(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         hits.fetch_add(1, SeqCst);
                     }
                 }
@@ -178,7 +178,7 @@ fn stress() {
         let mut expected = 0;
         while expected < COUNT {
             if rng.gen_range(0..3) == 0 {
-                while let Some(_) = w.pop() {
+                while w.pop().is_some() {
                     hits.fetch_add(1, SeqCst);
                 }
             } else {
@@ -188,7 +188,7 @@ fn stress() {
         }
 
         while hits.load(SeqCst) < COUNT {
-            while let Some(_) = w.pop() {
+            while w.pop().is_some() {
                 hits.fetch_add(1, SeqCst);
             }
         }
@@ -227,7 +227,7 @@ fn no_starvation() {
                         hits.fetch_add(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         hits.fetch_add(1, SeqCst);
                     }
                 }
@@ -239,7 +239,7 @@ fn no_starvation() {
         loop {
             for i in 0..rng.gen_range(0..COUNT) {
                 if rng.gen_range(0..3) == 0 && my_hits == 0 {
-                    while let Some(_) = w.pop() {
+                    while w.pop().is_some() {
                         my_hits += 1;
                     }
                 } else {
@@ -300,7 +300,7 @@ fn destructors() {
                         remaining.fetch_sub(1, SeqCst);
                     }
 
-                    while let Some(_) = w2.pop() {
+                    while w2.pop().is_some() {
                         cnt += 1;
                         remaining.fetch_sub(1, SeqCst);
                     }
@@ -309,7 +309,7 @@ fn destructors() {
         }
 
         for _ in 0..STEPS {
-            if let Some(_) = w.pop() {
+            if w.pop().is_some() {
                 remaining.fetch_sub(1, SeqCst);
             }
         }
diff --git a/crossbeam-epoch/src/atomic.rs b/crossbeam-epoch/src/atomic.rs
index 75a4714ef..a1bf1c5b8 100644
--- a/crossbeam-epoch/src/atomic.rs
+++ b/crossbeam-epoch/src/atomic.rs
@@ -1545,6 +1545,6 @@ mod tests {
     #[test]
     fn const_atomic_null() {
         use super::Atomic;
-        const _: Atomic<u8> = Atomic::<u8>::null();
+        static _U: Atomic<u8> = Atomic::<u8>::null();
     }
 }
diff --git a/crossbeam-skiplist/tests/base.rs b/crossbeam-skiplist/tests/base.rs
index 520344dd3..f08e1409e 100644
--- a/crossbeam-skiplist/tests/base.rs
+++ b/crossbeam-skiplist/tests/base.rs
@@ -164,7 +164,7 @@ fn len() {
     assert_eq!(s.len(), 0);
 
     for (i, &x) in [4, 2, 12, 8, 7, 11, 5].iter().enumerate() {
-        s.insert(x, x * 1, guard);
+        s.insert(x, x * 10, guard);
         assert_eq!(s.len(), i + 1);
     }
 
diff --git a/crossbeam-utils/tests/cache_padded.rs b/crossbeam-utils/tests/cache_padded.rs
index c9e768771..86e9a7709 100644
--- a/crossbeam-utils/tests/cache_padded.rs
+++ b/crossbeam-utils/tests/cache_padded.rs
@@ -85,6 +85,7 @@ fn drops() {
     assert_eq!(count.get(), 2);
 }
 
+#[allow(clippy::clone_on_copy)] // This is intentional.
 #[test]
 fn clone() {
     let a = CachePadded::new(17);
diff --git a/crossbeam-utils/tests/sharded_lock.rs b/crossbeam-utils/tests/sharded_lock.rs
index c36215440..b46d64a76 100644
--- a/crossbeam-utils/tests/sharded_lock.rs
+++ b/crossbeam-utils/tests/sharded_lock.rs
@@ -138,7 +138,7 @@ fn arc() {
 fn arc_access_in_unwind() {
     let arc = Arc::new(ShardedLock::new(1));
     let arc2 = arc.clone();
-    let _ = thread::spawn(move || -> () {
+    let _ = thread::spawn(move || {
         struct Unwinder {
             i: Arc<ShardedLock<isize>>,
         }