diff --git a/tests/AndroidManifest.xml b/tests/AndroidManifest.xml
index f84a545..eccd513 100644
--- a/tests/AndroidManifest.xml
+++ b/tests/AndroidManifest.xml
@@ -29,6 +29,7 @@
 
     <!-- TODO: Needed because we call ActivityManager.getCurrentUser() statically. -->
     <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS" />
+    <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS_FULL" />
     <uses-permission android:name="android.permission.MANAGE_USERS" />
 
     <!-- Used to access TelephonyManager APIs -->
diff --git a/tests/src/com/android/server/telecom/tests/ComponentContextFixture.java b/tests/src/com/android/server/telecom/tests/ComponentContextFixture.java
index 76929e7..fa5b6f0 100644
--- a/tests/src/com/android/server/telecom/tests/ComponentContextFixture.java
+++ b/tests/src/com/android/server/telecom/tests/ComponentContextFixture.java
@@ -259,6 +259,12 @@
         }
 
         @Override
+        public Intent registerReceiverAsUser(BroadcastReceiver receiver, UserHandle handle,
+                IntentFilter filter, String broadcastPermission, Handler scheduler) {
+            return null;
+        }
+
+        @Override
         public void sendBroadcast(Intent intent) {
             // TODO -- need to ensure this is captured
         }
diff --git a/tests/src/com/android/server/telecom/tests/DefaultDialerCacheTest.java b/tests/src/com/android/server/telecom/tests/DefaultDialerCacheTest.java
new file mode 100644
index 0000000..8ddcb1d
--- /dev/null
+++ b/tests/src/com/android/server/telecom/tests/DefaultDialerCacheTest.java
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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.android.server.telecom.tests;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.database.ContentObserver;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.UserHandle;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import com.android.server.telecom.DefaultDialerCache;
+import com.android.server.telecom.TelecomServiceImpl;
+import com.android.server.telecom.TelecomSystem;
+
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Matchers.isNull;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class DefaultDialerCacheTest extends TelecomTestCase {
+
+    private static final String DIALER1 = "com.android.dialer";
+    private static final String DIALER2 = "xyz.abc.dialer";
+    private static final String DIALER3 = "aaa.bbb.ccc.ddd";
+    private static final int USER0 = 0;
+    private static final int USER1 = 1;
+    private static final int USER2 = 2;
+
+    private DefaultDialerCache mDefaultDialerCache;
+    private ContentObserver mDefaultDialerSettingObserver;
+    private BroadcastReceiver mPackageChangeReceiver;
+
+    @Mock private TelecomServiceImpl.DefaultDialerManagerAdapter mMockDefaultDialerManager;
+
+    public void setUp() throws Exception {
+        super.setUp();
+        mContext = mComponentContextFixture.getTestDouble().getApplicationContext();
+
+        ArgumentCaptor<BroadcastReceiver> receiverCaptor =
+                ArgumentCaptor.forClass(BroadcastReceiver.class);
+
+        mDefaultDialerCache = new DefaultDialerCache(
+                mContext, mMockDefaultDialerManager, new TelecomSystem.SyncRoot() { });
+
+        verify(mContext).registerReceiverAsUser(
+                receiverCaptor.capture(), eq(UserHandle.ALL), any(IntentFilter.class),
+                isNull(String.class), isNull(Handler.class));
+        mPackageChangeReceiver = receiverCaptor.getValue();
+        mDefaultDialerSettingObserver = mDefaultDialerCache.getContentObserver();
+
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER0)))
+                .thenReturn(DIALER1);
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER1)))
+                .thenReturn(DIALER2);
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER2)))
+                .thenReturn(DIALER3);
+    }
+
+    @SmallTest
+    public void testThreeUsers() {
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER1));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+    }
+
+    @SmallTest
+    public void testDialer1PackageChanged() {
+        // Populate the caches first
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        Intent packageChangeIntent = new Intent(Intent.ACTION_PACKAGE_CHANGED,
+                Uri.fromParts("package", DIALER1, null));
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER0)))
+                .thenReturn(DIALER2);
+        mPackageChangeReceiver.onReceive(mContext, packageChangeIntent);
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER1));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER2);
+    }
+
+    @SmallTest
+    public void testRandomOtherPackageChanged() {
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        Intent packageChangeIntent = new Intent(Intent.ACTION_PACKAGE_CHANGED,
+                Uri.fromParts("package", "red.orange.blue", null));
+        mPackageChangeReceiver.onReceive(mContext, packageChangeIntent);
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER1));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+    }
+
+    @SmallTest
+    public void testPackageRemovedWithoutReplace() {
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        Intent packageChangeIntent = new Intent(Intent.ACTION_PACKAGE_REMOVED,
+                Uri.fromParts("package", DIALER1, null));
+        packageChangeIntent.putExtra(Intent.EXTRA_REPLACING, false);
+
+        mPackageChangeReceiver.onReceive(mContext, packageChangeIntent);
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER1));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+    }
+
+    @SmallTest
+    public void testPackageAdded() {
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        Intent packageChangeIntent = new Intent(Intent.ACTION_PACKAGE_ADDED,
+                Uri.fromParts("package", "ppp.qqq.zzz", null));
+
+        mPackageChangeReceiver.onReceive(mContext, packageChangeIntent);
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER1));
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+    }
+
+    @SmallTest
+    public void testPackageRemovedWithReplace() {
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        Intent packageChangeIntent = new Intent(Intent.ACTION_PACKAGE_REMOVED,
+                Uri.fromParts("package", DIALER1, null));
+        packageChangeIntent.putExtra(Intent.EXTRA_REPLACING, true);
+
+        mPackageChangeReceiver.onReceive(mContext, packageChangeIntent);
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER1));
+        verify(mMockDefaultDialerManager, times(1))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+    }
+
+    @SmallTest
+    public void testDefaultDialerSettingChanged() {
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER1);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER3);
+
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER0)))
+                .thenReturn(DIALER2);
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER1)))
+                .thenReturn(DIALER2);
+        when(mMockDefaultDialerManager.getDefaultDialerApplication(any(Context.class), eq(USER2)))
+                .thenReturn(DIALER2);
+        mDefaultDialerSettingObserver.onChange(false);
+
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER0));
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+        verify(mMockDefaultDialerManager, times(2))
+                .getDefaultDialerApplication(any(Context.class), eq(USER2));
+
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER0), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER1), DIALER2);
+        assertEquals(mDefaultDialerCache.getDefaultDialerApplication(USER2), DIALER2);
+    }
+}