diff --git a/kotlinx-coroutines-core/common/src/internal/LockFreeLinkedList.common.kt b/kotlinx-coroutines-core/common/src/internal/LockFreeLinkedList.common.kt
index 0e1d1b473a..8b20ade1f0 100644
--- a/kotlinx-coroutines-core/common/src/internal/LockFreeLinkedList.common.kt
+++ b/kotlinx-coroutines-core/common/src/internal/LockFreeLinkedList.common.kt
@@ -43,7 +43,7 @@ public expect open class LockFreeLinkedListNode() {
 public expect open class LockFreeLinkedListHead() : LockFreeLinkedListNode {
     public val isEmpty: Boolean
     public inline fun <reified T : LockFreeLinkedListNode> forEach(block: (T) -> Unit)
-    public final override fun remove(): Boolean // Actual return type is Nothing, KT-27534
+    public final override fun remove(): Nothing
 }
 
 /** @suppress **This is unstable API and it is subject to change.** */
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/DropTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/DropTest.kt
index 1c5a305352..dfa2827447 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/DropTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/DropTest.kt
@@ -48,10 +48,9 @@ class DropTest : TestBase() {
                 expectUnreached()
             }
         }.drop(1)
-            .map {
+            .map<Int, Int> {
                 expect(4)
                 throw TestException()
-                42
             }.catch { emit(42) }
 
         expect(1)
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/FilterTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/FilterTest.kt
index 3de5d54a6d..f52416d823 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/FilterTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/FilterTest.kt
@@ -38,7 +38,6 @@ class FilterTest : TestBase() {
         }.filter {
             latch.receive()
             throw TestException()
-            true
         }.catch { emit(42) }
 
         assertEquals(42, flow.single())
@@ -74,7 +73,6 @@ class FilterTest : TestBase() {
         }.filterNot {
             latch.receive()
             throw TestException()
-            true
         }.catch { emit(42) }
 
         assertEquals(42, flow.single())
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/FlatMapMergeBaseTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/FlatMapMergeBaseTest.kt
index 4095172dab..f09db120a8 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/FlatMapMergeBaseTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/FlatMapMergeBaseTest.kt
@@ -72,7 +72,7 @@ abstract class FlatMapMergeBaseTest : FlatMapBaseTest() {
             emit(2)
             expectUnreached()
         }.flatMap {
-            if (it == 1) flow<Int> {
+            if (it == 1) flow {
                 expect(5)
                 latch.send(Unit)
                 hang { expect(7) }
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/FlowOnTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/FlowOnTest.kt
index 68653281cc..8fba8456e8 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/FlowOnTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/FlowOnTest.kt
@@ -83,7 +83,7 @@ class FlowOnTest : TestBase() {
         }.map {
             expect(2)
             assertEquals("throwing", it)
-            throw TestException(); it
+            throw TestException()
         }.flowOn(NamedDispatchers("throwing"))
 
         assertFailsWith<TestException>(flow)
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/MapNotNullTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/MapNotNullTest.kt
index 893811df15..d8bb480054 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/MapNotNullTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/MapNotNullTest.kt
@@ -39,10 +39,9 @@ class MapNotNullTest : TestBase() {
                 }
                 emit(1)
             }
-        }.mapNotNull {
+        }.mapNotNull<Int, Int> {
             latch.receive()
             throw TestException()
-            it + 1
         }.catch { emit(42) }
 
         assertEquals(42, flow.single())
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/SampleTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/SampleTest.kt
index 87bee56f1d..f7741fbd59 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/SampleTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/SampleTest.kt
@@ -250,7 +250,6 @@ class SampleTest : TestBase() {
             expect(2)
             yield()
             throw TestException()
-            it
         }
 
         assertFailsWith<TestException>(flow)
diff --git a/kotlinx-coroutines-core/common/test/flow/operators/TakeTest.kt b/kotlinx-coroutines-core/common/test/flow/operators/TakeTest.kt
index 62d2322c04..ea8939fed2 100644
--- a/kotlinx-coroutines-core/common/test/flow/operators/TakeTest.kt
+++ b/kotlinx-coroutines-core/common/test/flow/operators/TakeTest.kt
@@ -88,9 +88,8 @@ class TakeTest : TestBase() {
                 emit(1)
             }
         }.take(2)
-            .map {
+            .map<Int, Int> {
                 throw TestException()
-                42
             }.catch { emit(42) }
 
         assertEquals(42, flow.single())
diff --git a/kotlinx-coroutines-core/js/src/internal/LinkedList.kt b/kotlinx-coroutines-core/js/src/internal/LinkedList.kt
index 147b31dc3e..d8c07f4e19 100644
--- a/kotlinx-coroutines-core/js/src/internal/LinkedList.kt
+++ b/kotlinx-coroutines-core/js/src/internal/LinkedList.kt
@@ -177,5 +177,5 @@ public open class LinkedListHead : LinkedListNode() {
     }
 
     // just a defensive programming -- makes sure that list head sentinel is never removed
-    public final override fun remove(): Boolean = throw UnsupportedOperationException()
+    public final override fun remove(): Nothing = throw UnsupportedOperationException()
 }
diff --git a/kotlinx-coroutines-core/jvm/src/internal/LockFreeLinkedList.kt b/kotlinx-coroutines-core/jvm/src/internal/LockFreeLinkedList.kt
index 9bbc6dc9eb..8b4517cb22 100644
--- a/kotlinx-coroutines-core/jvm/src/internal/LockFreeLinkedList.kt
+++ b/kotlinx-coroutines-core/jvm/src/internal/LockFreeLinkedList.kt
@@ -646,7 +646,7 @@ public actual open class LockFreeLinkedListHead : LockFreeLinkedListNode() {
     }
 
     // just a defensive programming -- makes sure that list head sentinel is never removed
-    public actual final override fun remove(): Boolean = error("head cannot be removed")
+    public actual final override fun remove(): Nothing = error("head cannot be removed")
 
     // optimization: because head is never removed, we don't have to read _next.value to check these:
     override val isRemoved: Boolean get() = false
diff --git a/kotlinx-coroutines-core/native/src/internal/LinkedList.kt b/kotlinx-coroutines-core/native/src/internal/LinkedList.kt
index a8aed04461..a161bc5bab 100644
--- a/kotlinx-coroutines-core/native/src/internal/LinkedList.kt
+++ b/kotlinx-coroutines-core/native/src/internal/LinkedList.kt
@@ -166,5 +166,5 @@ public open class LinkedListHead : LinkedListNode() {
     }
 
     // just a defensive programming -- makes sure that list head sentinel is never removed
-    public final override fun remove(): Boolean = throw UnsupportedOperationException()
+    public final override fun remove(): Nothing = throw UnsupportedOperationException()
 }
diff --git a/kotlinx-coroutines-core/native/test/TestBase.kt b/kotlinx-coroutines-core/native/test/TestBase.kt
index 4ffa6c0b11..1b12cefefe 100644
--- a/kotlinx-coroutines-core/native/test/TestBase.kt
+++ b/kotlinx-coroutines-core/native/test/TestBase.kt
@@ -78,7 +78,7 @@ public actual open class TestBase actual constructor() {
         var exCount = 0
         var ex: Throwable? = null
         try {
-            runBlocking(block = block, context = CoroutineExceptionHandler { context, e ->
+            runBlocking(block = block, context = CoroutineExceptionHandler { _, e ->
                 if (e is CancellationException) return@CoroutineExceptionHandler // are ignored
                 exCount++
                 when {