diff --git a/google-cloud-bigtable-emulator/src/main/java/com/google/cloud/bigtable/emulator/v2/Emulator.java b/google-cloud-bigtable-emulator/src/main/java/com/google/cloud/bigtable/emulator/v2/Emulator.java
index 9c2fa49b3..8e8cd5ad0 100644
--- a/google-cloud-bigtable-emulator/src/main/java/com/google/cloud/bigtable/emulator/v2/Emulator.java
+++ b/google-cloud-bigtable-emulator/src/main/java/com/google/cloud/bigtable/emulator/v2/Emulator.java
@@ -42,7 +42,6 @@
  */
 @BetaApi("Surface for Bigtable emulator is not yet stable")
 public class Emulator {
-
   private static final Logger LOGGER = Logger.getLogger(Emulator.class.getName());
 
   private final Path executable;
@@ -54,6 +53,9 @@ public class Emulator {
   private ManagedChannel dataChannel;
   private ManagedChannel adminChannel;
 
+  public static Emulator createFromPath(Path path) {
+    return new Emulator(path);
+  }
   /**
    * Create a new instance of emulator. The emulator will use the bundled binaries in this jar.
    * Please note that the emulator is created in a stopped state, please use {@link #start()} after
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableInstanceAdminSettingsTest.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableInstanceAdminSettingsTest.java
index 6fa6f3e4a..c6ccf9557 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableInstanceAdminSettingsTest.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableInstanceAdminSettingsTest.java
@@ -21,8 +21,11 @@
 import com.google.api.gax.rpc.StatusCode.Code;
 import java.io.IOException;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 import org.mockito.Mockito;
 
+@RunWith(JUnit4.class)
 public class BigtableInstanceAdminSettingsTest {
   @Test
   public void testProjectName() throws Exception {
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientTest.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientTest.java
index 2cda42b3e..c26551432 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientTest.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientTest.java
@@ -71,18 +71,22 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 import org.mockito.Matchers;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.invocation.InvocationOnMock;
-import org.mockito.runners.MockitoJUnitRunner;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
 import org.mockito.stubbing.Answer;
 import org.threeten.bp.Instant;
 
-@RunWith(MockitoJUnitRunner.class)
+@RunWith(JUnit4.class)
 public class BigtableTableAdminClientTest {
+  @Rule public final MockitoRule mockitoRule = MockitoJUnit.rule();
 
   private static final String PROJECT_ID = "my-project";
   private static final String INSTANCE_ID = "my-instance";
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminSettingsTest.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminSettingsTest.java
index 3a16dd236..77ce733ce 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminSettingsTest.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminSettingsTest.java
@@ -21,8 +21,11 @@
 import com.google.api.gax.rpc.StatusCode.Code;
 import java.io.IOException;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 import org.mockito.Mockito;
 
+@RunWith(JUnit4.class)
 public class BigtableTableAdminSettingsTest {
 
   @Test
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableBackupIT.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableBackupIT.java
index 1e1bc8464..4d17bbf0e 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableBackupIT.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableBackupIT.java
@@ -47,9 +47,12 @@
 import java.util.concurrent.TimeoutException;
 import java.util.logging.Logger;
 import org.junit.*;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 import org.threeten.bp.Duration;
 import org.threeten.bp.Instant;
 
+@RunWith(JUnit4.class)
 public class BigtableBackupIT {
   private static final Logger LOGGER = Logger.getLogger(BigtableBackupIT.class.getName());
 
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableInstanceAdminClientIT.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableInstanceAdminClientIT.java
index f31654334..9b41444c7 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableInstanceAdminClientIT.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableInstanceAdminClientIT.java
@@ -40,8 +40,11 @@
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 import org.threeten.bp.Instant;
 
+@RunWith(JUnit4.class)
 public class BigtableInstanceAdminClientIT {
 
   @ClassRule public static TestEnvRule testEnvRule = new TestEnvRule();
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableTableAdminClientIT.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableTableAdminClientIT.java
index 333fa875c..2dc64b640 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableTableAdminClientIT.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableTableAdminClientIT.java
@@ -46,8 +46,11 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TestName;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 import org.threeten.bp.Duration;
 
+@RunWith(JUnit4.class)
 public class BigtableTableAdminClientIT {
   @ClassRule public static TestEnvRule testEnvRule = new TestEnvRule();
   @Rule public final TestName testNameRule = new TestName();
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/models/ReadModifyWriteRowTest.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/models/ReadModifyWriteRowTest.java
index b9e6f9e7b..b0a8be33c 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/models/ReadModifyWriteRowTest.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/models/ReadModifyWriteRowTest.java
@@ -28,7 +28,10 @@
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 
+@RunWith(JUnit4.class)
 public class ReadModifyWriteRowTest {
   private static final String PROJECT_ID = "fake-project";
   private static final String INSTANCE_ID = "fake-instance";
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/stub/EnhancedBigtableStubTest.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/stub/EnhancedBigtableStubTest.java
index b823930fb..6d0ba10bf 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/stub/EnhancedBigtableStubTest.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/stub/EnhancedBigtableStubTest.java
@@ -138,11 +138,11 @@ public void testChannelPrimerConfigured() throws IOException {
   }
 
   private static class FakeDataService extends BigtableGrpc.BigtableImplBase {
-    final BlockingQueue<Object> requests = Queues.newLinkedBlockingDeque();
+    final BlockingQueue<ReadRowsRequest> requests = Queues.newLinkedBlockingDeque();
 
     @SuppressWarnings("unchecked")
-    <T> T popLastRequest() throws InterruptedException {
-      return (T) requests.poll(1, TimeUnit.SECONDS);
+    ReadRowsRequest popLastRequest() throws InterruptedException {
+      return requests.poll(1, TimeUnit.SECONDS);
     }
 
     @Override
diff --git a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/test_helpers/env/EmulatorEnv.java b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/test_helpers/env/EmulatorEnv.java
index f3e97584e..d1740fbfc 100644
--- a/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/test_helpers/env/EmulatorEnv.java
+++ b/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/test_helpers/env/EmulatorEnv.java
@@ -22,8 +22,12 @@
 import com.google.cloud.bigtable.data.v2.BigtableDataClient;
 import com.google.cloud.bigtable.data.v2.BigtableDataSettings;
 import com.google.cloud.bigtable.emulator.v2.Emulator;
+import com.google.common.base.Strings;
+import java.nio.file.Paths;
 
 public class EmulatorEnv extends AbstractTestEnv {
+  private static final String EMULATOR_OVERRIDE_PROPERTY_NAME = "bigtable.emulator-path";
+
   private static final String PROJECT_ID = "fake-project";
   private static final String INSTANCE_ID = "fake-instance";
   private static final String TABLE_ID = "default-table";
@@ -42,7 +46,12 @@ private EmulatorEnv() {}
 
   @Override
   void start() throws Exception {
-    emulator = Emulator.createBundled();
+    String overridePath = System.getProperty(EMULATOR_OVERRIDE_PROPERTY_NAME);
+    if (!Strings.isNullOrEmpty(overridePath)) {
+      emulator = Emulator.createFromPath(Paths.get(overridePath));
+    } else {
+      emulator = Emulator.createBundled();
+    }
     emulator.start();
 
     dataSettings =