diff --git a/google-cloud-pubsub/pom.xml b/google-cloud-pubsub/pom.xml
index 4ce3d92ddb7f..68c7e57e3c0a 100644
--- a/google-cloud-pubsub/pom.xml
+++ b/google-cloud-pubsub/pom.xml
@@ -72,12 +72,6 @@
       <version>3.4</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-        <groupId>org.mockito</groupId>
-        <artifactId>mockito-all</artifactId>
-        <version>1.9.5</version>
-        <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>com.google.truth</groupId>
       <artifactId>truth</artifactId>
diff --git a/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/FakePublisherServiceImpl.java b/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/FakePublisherServiceImpl.java
index 162898fa7c07..01f3dd58846c 100644
--- a/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/FakePublisherServiceImpl.java
+++ b/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/FakePublisherServiceImpl.java
@@ -21,6 +21,8 @@
 import com.google.pubsub.v1.PublishResponse;
 import com.google.pubsub.v1.PublisherGrpc.PublisherImplBase;
 import io.grpc.stub.StreamObserver;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.LinkedBlockingQueue;
 
 /**
@@ -29,6 +31,7 @@
  */
 class FakePublisherServiceImpl extends PublisherImplBase {
 
+  private final LinkedBlockingQueue<PublishRequest> requests = new LinkedBlockingQueue<>();
   private final LinkedBlockingQueue<Response> publishResponses = new LinkedBlockingQueue<>();
 
   /** Class used to save the state of a possible response. */
@@ -69,6 +72,7 @@ public String toString() {
 
   @Override
   public void publish(PublishRequest request, StreamObserver<PublishResponse> responseObserver) {
+    requests.add(request);
     Response response;
     try {
       response = publishResponses.take();
@@ -98,7 +102,7 @@ public FakePublisherServiceImpl addPublishError(Throwable error) {
     return this;
   }
 
-  public void reset() {
-    publishResponses.clear();
+  public List<PublishRequest> getCapturedRequests() {
+    return new ArrayList<PublishRequest>(requests);
   }
 }
diff --git a/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/PublisherImplTest.java b/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/PublisherImplTest.java
index 8a96e8823928..9b0e961cda6b 100644
--- a/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/PublisherImplTest.java
+++ b/google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/spi/v1/PublisherImplTest.java
@@ -18,21 +18,19 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
-import static org.mockito.Mockito.atLeast;
-import static org.mockito.Mockito.times;
 
 import com.google.api.gax.bundling.BundlingSettings;
+import com.google.api.gax.core.ApiFuture;
 import com.google.api.gax.core.FlowControlSettings;
 import com.google.api.gax.core.FlowController.LimitExceededBehavior;
-import com.google.api.gax.core.ApiFuture;
 import com.google.api.gax.grpc.ChannelProvider;
 import com.google.api.gax.grpc.ExecutorProvider;
 import com.google.api.gax.grpc.FixedExecutorProvider;
 import com.google.api.gax.grpc.InstantiatingExecutorProvider;
 import com.google.cloud.pubsub.spi.v1.Publisher.Builder;
 import com.google.protobuf.ByteString;
-import com.google.pubsub.v1.PublishRequest;
 import com.google.pubsub.v1.PublishResponse;
 import com.google.pubsub.v1.PubsubMessage;
 import com.google.pubsub.v1.TopicName;
@@ -42,7 +40,6 @@
 import io.grpc.inprocess.InProcessChannelBuilder;
 import io.grpc.inprocess.InProcessServerBuilder;
 import io.grpc.internal.ServerImpl;
-import io.grpc.stub.StreamObserver;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import org.joda.time.Duration;
@@ -51,10 +48,6 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Captor;
-import org.mockito.Mockito;
-import org.mockito.MockitoAnnotations;
 
 @RunWith(JUnit4.class)
 public class PublisherImplTest {
@@ -87,8 +80,6 @@ public ManagedChannel getChannel(Executor executor) {
         }
       };
 
-  @Captor private ArgumentCaptor<PublishRequest> requestCaptor;
-
   private FakeScheduledExecutorService fakeExecutor;
 
   private FakeCredentials testCredentials;
@@ -101,16 +92,13 @@ class FakeException extends Exception {}
 
   @Before
   public void setUp() throws Exception {
-    testPublisherServiceImpl = Mockito.spy(new FakePublisherServiceImpl());
+    testPublisherServiceImpl = new FakePublisherServiceImpl();
 
     InProcessServerBuilder serverBuilder = InProcessServerBuilder.forName("test-server");
     serverBuilder.addService(testPublisherServiceImpl);
     testServer = serverBuilder.build();
     testServer.start();
 
-    MockitoAnnotations.initMocks(this);
-    testPublisherServiceImpl.reset();
-    Mockito.reset(testPublisherServiceImpl);
     fakeExecutor = new FakeScheduledExecutorService();
   }
 
@@ -146,9 +134,7 @@ public void testPublishByDuration() throws Exception {
     assertEquals("1", publishFuture1.get());
     assertEquals("2", publishFuture2.get());
 
-    Mockito.verify(testPublisherServiceImpl)
-        .publish(requestCaptor.capture(), Mockito.<StreamObserver<PublishResponse>>any());
-    assertEquals(2, requestCaptor.getValue().getMessagesCount());
+    assertEquals(2, testPublisherServiceImpl.getCapturedRequests().get(0).getMessagesCount());
     publisher.shutdown();
   }
 
@@ -185,10 +171,8 @@ public void testPublishByNumBundledMessages() throws Exception {
     assertEquals("3", publishFuture3.get());
     assertEquals("4", publishFuture4.get());
 
-    Mockito.verify(testPublisherServiceImpl, times(2))
-        .publish(requestCaptor.capture(), Mockito.<StreamObserver<PublishResponse>>any());
-    assertEquals(2, requestCaptor.getAllValues().get(0).getMessagesCount());
-    assertEquals(2, requestCaptor.getAllValues().get(1).getMessagesCount());
+    assertEquals(2, testPublisherServiceImpl.getCapturedRequests().get(0).getMessagesCount());
+    assertEquals(2, testPublisherServiceImpl.getCapturedRequests().get(1).getMessagesCount());
     publisher.shutdown();
   }
 
@@ -222,8 +206,7 @@ public void testSinglePublishByNumBytes() throws Exception {
     assertEquals("3", publishFuture3.get());
     assertEquals("4", publishFuture4.get());
 
-    Mockito.verify(testPublisherServiceImpl, times(2))
-        .publish(requestCaptor.capture(), Mockito.<StreamObserver<PublishResponse>>any());
+    assertEquals(2, testPublisherServiceImpl.getCapturedRequests().size());
     publisher.shutdown();
   }
 
@@ -264,10 +247,8 @@ public void testPublishMixedSizeAndDuration() throws Exception {
 
     assertEquals("3", publishFuture3.get());
 
-    Mockito.verify(testPublisherServiceImpl, times(2))
-        .publish(requestCaptor.capture(), Mockito.<StreamObserver<PublishResponse>>any());
-    assertEquals(2, requestCaptor.getAllValues().get(0).getMessagesCount());
-    assertEquals(1, requestCaptor.getAllValues().get(1).getMessagesCount());
+    assertEquals(2, testPublisherServiceImpl.getCapturedRequests().get(0).getMessagesCount());
+    assertEquals(1, testPublisherServiceImpl.getCapturedRequests().get(1).getMessagesCount());
     publisher.shutdown();
   }
 
@@ -296,8 +277,7 @@ public void testPublishFailureRetries() throws Exception {
 
     assertEquals("1", publishFuture1.get());
 
-    Mockito.verify(testPublisherServiceImpl, times(2))
-        .publish(Mockito.<PublishRequest>any(), Mockito.<StreamObserver<PublishResponse>>any());
+    assertEquals(2, testPublisherServiceImpl.getCapturedRequests().size());
     publisher.shutdown();
   }
 
@@ -331,8 +311,7 @@ public void testPublishFailureRetries_exceededsRetryDuration() throws Exception
         throw new IllegalStateException("unexpected exception", e);
       }
     } finally {
-      Mockito.verify(testPublisherServiceImpl, atLeast(10))
-          .publish(Mockito.<PublishRequest>any(), Mockito.<StreamObserver<PublishResponse>>any());
+      assertTrue(testPublisherServiceImpl.getCapturedRequests().size() >= 10);
       publisher.shutdown();
     }
   }
@@ -361,8 +340,7 @@ public void testPublishFailureRetries_nonRetryableFailsImmediately() throws Exce
     try {
       publishFuture1.get();
     } finally {
-      Mockito.verify(testPublisherServiceImpl)
-          .publish(Mockito.<PublishRequest>any(), Mockito.<StreamObserver<PublishResponse>>any());
+      assertTrue(testPublisherServiceImpl.getCapturedRequests().size() >= 1);
       publisher.shutdown();
     }
   }