diff --git a/android/guava-tests/test/com/google/common/base/AbstractIteratorTest.java b/android/guava-tests/test/com/google/common/base/AbstractIteratorTest.java
index 7dc3d0274017..76277dad2c46 100644
--- a/android/guava-tests/test/com/google/common/base/AbstractIteratorTest.java
+++ b/android/guava-tests/test/com/google/common/base/AbstractIteratorTest.java
@@ -28,6 +28,7 @@
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import junit.framework.TestCase;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Unit test for {@code AbstractIterator}.
@@ -46,7 +47,7 @@ public void testDefaultBehaviorOfNextAndHasNext() {
           private int rep;
 
           @Override
-          public Integer computeNext() {
+          public @Nullable Integer computeNext() {
             switch (rep++) {
               case 0:
                 return 0;
diff --git a/android/guava-tests/test/com/google/common/base/ToStringHelperTest.java b/android/guava-tests/test/com/google/common/base/ToStringHelperTest.java
index c0bf9b25ce76..692a8382ee93 100644
--- a/android/guava-tests/test/com/google/common/base/ToStringHelperTest.java
+++ b/android/guava-tests/test/com/google/common/base/ToStringHelperTest.java
@@ -28,6 +28,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import junit.framework.TestCase;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Tests for {@link MoreObjects#toStringHelper(Object)}.
@@ -580,7 +581,7 @@ public void testToStringHelperWithArrays() {
     String[] strings = {"hello", "world"};
     int[] ints = {2, 42};
     Object[] objects = {"obj"};
-    String[] arrayWithNull = {null};
+    @Nullable String[] arrayWithNull = new @Nullable String[] {null};
     Object[] empty = {};
     String toTest =
         MoreObjects.toStringHelper("TSH")
diff --git a/android/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java b/android/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java
index df112c169776..3c77ac3b2070 100644
--- a/android/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java
+++ b/android/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java
@@ -155,10 +155,10 @@ public void onFailure(Throwable t) {
   public void testWildcardFuture() {
     SettableFuture<String> settable = SettableFuture.create();
     ListenableFuture<?> f = settable;
-    FutureCallback<Object> callback =
-        new FutureCallback<Object>() {
+    FutureCallback<@Nullable Object> callback =
+        new FutureCallback<@Nullable Object>() {
           @Override
-          public void onSuccess(Object result) {}
+          public void onSuccess(@Nullable Object result) {}
 
           @Override
           public void onFailure(Throwable t) {}
diff --git a/android/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java b/android/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java
index 501e52d828d9..91df560584e7 100644
--- a/android/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java
+++ b/android/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java
@@ -29,6 +29,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeoutException;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /** Methods factored out so that they can be emulated differently in GWT. */
 @GwtCompatible(emulated = true)
@@ -66,7 +67,8 @@ static void clearInterrupt() {
    * Retrieves the result of a {@code Future} known to be done but uses the {@code get(long,
    * TimeUnit)} overload in order to test that method.
    */
-  static <V> V getDoneFromTimeoutOverload(Future<V> future) throws ExecutionException {
+  static <V extends @Nullable Object> V getDoneFromTimeoutOverload(Future<V> future)
+      throws ExecutionException {
     checkState(future.isDone(), "Future was expected to be done: %s", future);
     try {
       return getUninterruptibly(future, 0, SECONDS);
diff --git a/guava-gwt/test-super/com/google/common/util/concurrent/super/com/google/common/util/concurrent/TestPlatform.java b/guava-gwt/test-super/com/google/common/util/concurrent/super/com/google/common/util/concurrent/TestPlatform.java
index 7767869b594c..1cca355bea71 100644
--- a/guava-gwt/test-super/com/google/common/util/concurrent/super/com/google/common/util/concurrent/TestPlatform.java
+++ b/guava-gwt/test-super/com/google/common/util/concurrent/super/com/google/common/util/concurrent/TestPlatform.java
@@ -24,6 +24,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeoutException;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /** Methods factored out so that they can be emulated differently in GWT. */
 final class TestPlatform {
@@ -55,7 +56,8 @@ static void clearInterrupt() {
     // There is no thread interruption in GWT, so there's nothing to do.
   }
 
-  static <V> V getDoneFromTimeoutOverload(Future<V> future) throws ExecutionException {
+  static <V extends @Nullable Object> V getDoneFromTimeoutOverload(Future<V> future)
+      throws ExecutionException {
     checkState(future.isDone(), "Future was expected to be done: %s", future);
     try {
       return future.get(0, SECONDS);
diff --git a/guava-tests/test/com/google/common/base/AbstractIteratorTest.java b/guava-tests/test/com/google/common/base/AbstractIteratorTest.java
index 7dc3d0274017..76277dad2c46 100644
--- a/guava-tests/test/com/google/common/base/AbstractIteratorTest.java
+++ b/guava-tests/test/com/google/common/base/AbstractIteratorTest.java
@@ -28,6 +28,7 @@
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import junit.framework.TestCase;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Unit test for {@code AbstractIterator}.
@@ -46,7 +47,7 @@ public void testDefaultBehaviorOfNextAndHasNext() {
           private int rep;
 
           @Override
-          public Integer computeNext() {
+          public @Nullable Integer computeNext() {
             switch (rep++) {
               case 0:
                 return 0;
diff --git a/guava-tests/test/com/google/common/base/ToStringHelperTest.java b/guava-tests/test/com/google/common/base/ToStringHelperTest.java
index 21e53d90814f..e8f9eb92eb23 100644
--- a/guava-tests/test/com/google/common/base/ToStringHelperTest.java
+++ b/guava-tests/test/com/google/common/base/ToStringHelperTest.java
@@ -31,6 +31,7 @@
 import java.util.OptionalInt;
 import java.util.OptionalLong;
 import junit.framework.TestCase;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Tests for {@link MoreObjects#toStringHelper(Object)}.
@@ -591,7 +592,7 @@ public void testToStringHelperWithArrays() {
     String[] strings = {"hello", "world"};
     int[] ints = {2, 42};
     Object[] objects = {"obj"};
-    String[] arrayWithNull = {null};
+    @Nullable String[] arrayWithNull = new @Nullable String[] {null};
     Object[] empty = {};
     String toTest =
         MoreObjects.toStringHelper("TSH")
diff --git a/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java b/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java
index df112c169776..3c77ac3b2070 100644
--- a/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java
+++ b/guava-tests/test/com/google/common/util/concurrent/FutureCallbackTest.java
@@ -155,10 +155,10 @@ public void onFailure(Throwable t) {
   public void testWildcardFuture() {
     SettableFuture<String> settable = SettableFuture.create();
     ListenableFuture<?> f = settable;
-    FutureCallback<Object> callback =
-        new FutureCallback<Object>() {
+    FutureCallback<@Nullable Object> callback =
+        new FutureCallback<@Nullable Object>() {
           @Override
-          public void onSuccess(Object result) {}
+          public void onSuccess(@Nullable Object result) {}
 
           @Override
           public void onFailure(Throwable t) {}
diff --git a/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java b/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java
index 501e52d828d9..91df560584e7 100644
--- a/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java
+++ b/guava-tests/test/com/google/common/util/concurrent/TestPlatform.java
@@ -29,6 +29,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeoutException;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /** Methods factored out so that they can be emulated differently in GWT. */
 @GwtCompatible(emulated = true)
@@ -66,7 +67,8 @@ static void clearInterrupt() {
    * Retrieves the result of a {@code Future} known to be done but uses the {@code get(long,
    * TimeUnit)} overload in order to test that method.
    */
-  static <V> V getDoneFromTimeoutOverload(Future<V> future) throws ExecutionException {
+  static <V extends @Nullable Object> V getDoneFromTimeoutOverload(Future<V> future)
+      throws ExecutionException {
     checkState(future.isDone(), "Future was expected to be done: %s", future);
     try {
       return getUninterruptibly(future, 0, SECONDS);