diff --git a/src/main/java/com/google/gcloud/datastore/DatastoreHelper.java b/src/main/java/com/google/gcloud/datastore/DatastoreHelper.java
index 0b0558e565fd..6b89b9f3ab2a 100644
--- a/src/main/java/com/google/gcloud/datastore/DatastoreHelper.java
+++ b/src/main/java/com/google/gcloud/datastore/DatastoreHelper.java
@@ -109,7 +109,7 @@ public void delete(Key... key) {
    * Returns a new KeyFactory for this service
    */
   public KeyFactory newKeyFactory() {
-    return new KeyFactory(this);
+    return new KeyFactory(delegate);
   }
 
   /**
diff --git a/src/test/java/com/google/gcloud/datastore/DatastoreHelperTest.java b/src/test/java/com/google/gcloud/datastore/DatastoreHelperTest.java
new file mode 100644
index 000000000000..531f5dd517da
--- /dev/null
+++ b/src/test/java/com/google/gcloud/datastore/DatastoreHelperTest.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright 2015 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.gcloud.datastore;
+
+import static junit.framework.TestCase.assertTrue;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.createStrictMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
+
+import com.google.api.services.datastore.client.Datastore;
+import com.google.common.collect.Iterators;
+import com.google.common.collect.Sets;
+
+import org.junit.Test;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class DatastoreHelperTest {
+
+  @Test
+  public void testDelegate() throws Exception {
+    final Set<Method> methods = Sets.newHashSet(DatastoreService.class.getMethods());
+    final Map<String, Object[]> params = new HashMap<>();
+    InvocationHandler handler = new InvocationHandler() {
+      @Override
+      public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
+        String methodName = Thread.currentThread().getStackTrace()[3].getMethodName();
+        if (method.getParameterTypes().length > 0) {
+          Class paramClass = method.getParameterTypes()[0];
+          methodName += paramClass.getSimpleName();
+          if (method.isVarArgs()) {
+            objects = (Object[]) objects[0];
+          }
+          assertArrayEquals(objects, params.get(methodName));
+        }
+        assertTrue(methods.remove(method));
+        return null;
+      }
+    };
+    PartialKey pKey1 = PartialKey.builder("ds", "k").build();
+    PartialKey pKey2 = PartialKey.builder("ds", "k").build();
+    PartialEntity pEntity1 = PartialEntity.builder(pKey1).build();
+    PartialEntity pEntity2 = PartialEntity.builder(pKey2).build();
+    Key key1 = Key.builder(pKey1, 1).build();
+    Key key2 = Key.builder(pKey1, "a").build();
+    Entity entity1 = Entity.builder(key1).build();
+    Entity entity2 = Entity.builder(key2).build();
+    ClassLoader cl = DatastoreService.class.getClassLoader();
+    Class<?>[] interfaces = DatastoreHelper.class.getInterfaces();
+    DatastoreService delegate = (DatastoreService) Proxy.newProxyInstance(cl, interfaces, handler);
+    DatastoreHelper helper = DatastoreHelper.createFor(delegate);
+    params.put("getKey", new Object[] {key1});
+    helper.get(key1);
+    params.put("getKey[]", new Object[] {key1, key2});
+    helper.get(key1, key2);
+    params.put("addEntity[]", new Object[] {entity1, entity2});
+    helper.add(entity1, entity2);
+    params.put("updateEntity[]", new Object[] {entity1});
+    helper.update(entity1);
+    params.put("addPartialEntity", new Object[] {pEntity1});
+    helper.add(pEntity1);
+    params.put("addPartialEntity[]", new Object[] {pEntity2, entity1});
+    helper.add(pEntity2, entity1);
+    params.put("allocateIdPartialKey", new Object[] {pKey1});
+    helper.allocateId(pKey1);
+    params.put("allocateIdPartialKey[]", new Object[] {pKey1, pKey2});
+    helper.allocateId(pKey1, pKey2);
+    params.put("deleteKey[]", new Object[] {key1});
+    helper.delete(key1);
+    params.put("putEntity[]", new Object[] {entity1});
+    helper.put(entity1);
+    helper.options();
+    params.put("newBatchBatchOption[]", new Object[] {});
+    helper.newBatch();
+    params.put("newTransactionTransactionOption[]", new Object[] {});
+    helper.newTransaction();
+    Query query = createMock(Query.class);
+    params.put("runQuery", new Object[] {query});
+    helper.run(query);
+    assertTrue(methods.isEmpty());
+  }
+
+  @Test
+  public void testNewKeyFactory() throws Exception {
+    DatastoreService datastoreService = createStrictMock(DatastoreService.class);
+    Datastore datastore = createStrictMock(Datastore.class);
+    DatastoreServiceOptions options =
+        DatastoreServiceOptions.builder().normalizeDataset(false).datastore(datastore)
+            .dataset("ds").build();
+    expect(datastoreService.options()).andReturn(options).atLeastOnce();
+    replay(datastore, datastoreService);
+    DatastoreHelper helper = DatastoreHelper.createFor(datastoreService);
+    KeyFactory keyFactory = helper.newKeyFactory();
+    assertSame(datastoreService, keyFactory.datastore());
+    verify(datastore, datastoreService);
+  }
+
+  @Test
+  public void testFetch() throws Exception {
+    DatastoreService datastoreService = createStrictMock(DatastoreService.class);
+    PartialKey pKey1 = PartialKey.builder("ds", "k").build();
+    Key key1 = Key.builder(pKey1, 1).build();
+    Key key2 = Key.builder(pKey1, "a").build();
+    Entity entity1 = Entity.builder(key1).build();
+    Entity entity2 = Entity.builder(key2).build();
+    expect(datastoreService.get(key1, key2)).andReturn(Iterators.forArray(entity1, entity2)).once();
+    replay(datastoreService);
+    DatastoreHelper helper = DatastoreHelper.createFor(datastoreService);
+    List<Entity> values = helper.fetch(key1, key2);
+    assertEquals(2, values.size());
+    assertEquals(entity1, values.get(0));
+    assertEquals(entity2, values.get(1));
+    verify(datastoreService);
+  }
+
+  @Test
+  public void testRunInTransaction() throws Exception {
+    final DatastoreService datastoreService = createStrictMock(DatastoreService.class);
+    final Transaction transaction = createStrictMock(Transaction.class);
+    expect(datastoreService.newTransaction()).andReturn(transaction).once();
+    expect(transaction.active()).andReturn(true).once();
+    expect(transaction.commit()).andReturn(null).once();
+    expect(transaction.active()).andReturn(false).once();
+    replay(datastoreService, transaction);
+    DatastoreHelper helper = DatastoreHelper.createFor(datastoreService);
+    helper.runInTransaction(new DatastoreHelper.RunInTransaction() {
+      @Override
+      public void run(DatastoreReaderWriter readerWriter) {
+        assertTrue(transaction.active());
+        assertSame(transaction, readerWriter);
+      }
+    });
+    verify(datastoreService, transaction);
+  }
+}