diff --git a/src/com/android/dialer/calllog/CallLogNotificationsHelper.java b/src/com/android/dialer/calllog/CallLogNotificationsHelper.java
index 1892631..9a50284 100644
--- a/src/com/android/dialer/calllog/CallLogNotificationsHelper.java
+++ b/src/com/android/dialer/calllog/CallLogNotificationsHelper.java
@@ -16,6 +16,8 @@
 
 package com.android.dialer.calllog;
 
+import com.google.common.base.Strings;
+
 import android.Manifest;
 import android.content.ContentResolver;
 import android.content.ContentUris;
@@ -112,12 +114,13 @@
      * Otherwise attempt to look it up in the cache.
      * If that fails, fall back to displaying the number.
      */
-    public @NonNull ContactInfo getContactInfo(@Nullable String number, int numberPresentation,
+    public ContactInfo getContactInfo(@Nullable String number, int numberPresentation,
                           @Nullable String countryIso) {
         if (countryIso == null) {
             countryIso = mCurrentCountryIso;
         }
 
+        number = Strings.nullToEmpty(number);
         ContactInfo contactInfo = new ContactInfo();
         contactInfo.number = number;
         contactInfo.formattedNumber = PhoneNumberUtils.formatNumber(number, countryIso);
diff --git a/tests/src/com/android/dialer/calllog/CallLogNotificationsHelperTest.java b/tests/src/com/android/dialer/calllog/CallLogNotificationsHelperTest.java
new file mode 100644
index 0000000..b5950d8
--- /dev/null
+++ b/tests/src/com/android/dialer/calllog/CallLogNotificationsHelperTest.java
@@ -0,0 +1,137 @@
+/*
+ * 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.dialer.calllog;
+
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import android.provider.CallLog;
+import android.test.AndroidTestCase;
+
+import com.android.dialer.R;
+
+/**
+ * Unit tests for {@link CallLogNotificationsHelper}.
+ */
+public class CallLogNotificationsHelperTest extends AndroidTestCase {
+    private static final String TEST_COUNTRY_ISO = "US";
+    private static final String TEST_VALID_NUMBER = "14125555555";
+    private static final String TEST_INVALID_NUMBER = "asdna128937123";
+    private static final String TEST_FORMATTED_NUMBER = "1 412-555-5555";
+    private static final String TEST_E164_NUMBER = "+14125555555";
+
+    private final ContactInfoHelper mContactInfoHelper = mock(ContactInfoHelper.class);
+
+    private CallLogNotificationsHelper mCallLogNotificationsHelper;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        mCallLogNotificationsHelper = new CallLogNotificationsHelper(getContext(),
+                null, null, mContactInfoHelper, TEST_COUNTRY_ISO);
+    }
+
+    public void testGetContactInfo_ValidNumberValidPresentationValidIso() {
+        ContactInfo contactInfo = getContactInfo(
+                TEST_VALID_NUMBER, CallLog.Calls.PRESENTATION_UNKNOWN, TEST_COUNTRY_ISO);
+        assertEquals(TEST_VALID_NUMBER, contactInfo.number);
+        assertEquals(mContext.getResources().getString(R.string.unknown), contactInfo.name);
+        assertEquals(TEST_E164_NUMBER, contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_ValidNumberInvalidPresentationValidIso() {
+        ContactInfo contactInfo = getContactInfo(TEST_VALID_NUMBER, -1, TEST_COUNTRY_ISO);
+        assertEquals(TEST_VALID_NUMBER, contactInfo.number);
+        assertEquals(TEST_FORMATTED_NUMBER, contactInfo.name);
+        assertEquals(TEST_E164_NUMBER, contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_ValidNumberValidPresentationNullIso() {
+        ContactInfo contactInfo = getContactInfo(
+                TEST_VALID_NUMBER, CallLog.Calls.PRESENTATION_UNKNOWN, null);
+        assertEquals(TEST_VALID_NUMBER, contactInfo.number);
+        assertEquals(mContext.getResources().getString(R.string.unknown), contactInfo.name);
+        assertEquals(TEST_E164_NUMBER, contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_ValidNumberInvalidPresentationNullIso() {
+        ContactInfo contactInfo = getContactInfo(
+                TEST_VALID_NUMBER, -1, null);
+        assertEquals(TEST_VALID_NUMBER, contactInfo.number);
+        assertEquals(TEST_FORMATTED_NUMBER, contactInfo.name);
+        assertEquals(TEST_E164_NUMBER, contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_NullNumberValidPresentationValidIso() {
+        ContactInfo contactInfo = getContactInfo(
+                null, CallLog.Calls.PRESENTATION_UNKNOWN, TEST_COUNTRY_ISO);
+        assertEquals("", contactInfo.number);
+        assertEquals(mContext.getResources().getString(R.string.unknown), contactInfo.name);
+        assertNull(contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_NullNumberInvalidPresentationValidIso() {
+        ContactInfo contactInfo = getContactInfo(null, -1, TEST_COUNTRY_ISO);
+        assertEquals("", contactInfo.number);
+        assertEquals(mContext.getResources().getString(R.string.unknown), contactInfo.name);
+        assertNull(contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_NullNumberValidPresentationNullIso() {
+        ContactInfo contactInfo = getContactInfo(null, CallLog.Calls.PRESENTATION_RESTRICTED, null);
+        assertEquals("", contactInfo.number);
+        assertEquals(mContext.getResources().getString(R.string.private_num), contactInfo.name);
+        assertNull(contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_NullNumberInValidPresentationNullIso() {
+        ContactInfo contactInfo = getContactInfo(null, -1, null);
+        assertEquals("", contactInfo.number);
+        assertEquals(mContext.getResources().getString(R.string.unknown), contactInfo.name);
+        assertNull(contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_InvalidNumberInValidPresentationNullIso() {
+        ContactInfo contactInfo = getContactInfo(TEST_INVALID_NUMBER, -1, null);
+        assertEquals(TEST_INVALID_NUMBER, contactInfo.name);
+        assertEquals(TEST_INVALID_NUMBER, contactInfo.formattedNumber);
+        assertEquals(null, contactInfo.normalizedNumber);
+    }
+
+    public void testGetContactInfo_NonNullCachedLookup() {
+        when(mContactInfoHelper.lookupNumber(anyString(), anyString())).thenReturn(null);
+        ContactInfo contactInfo = getContactInfo(TEST_VALID_NUMBER, -1, TEST_COUNTRY_ISO);
+        assertEquals(TEST_VALID_NUMBER, contactInfo.number);
+        assertEquals(TEST_FORMATTED_NUMBER, contactInfo.formattedNumber);
+    }
+
+    public void testGetContactInfo_NullCachedLookup() {
+        ContactInfo cachedContactInfo = new ContactInfo();
+        cachedContactInfo.number = TEST_VALID_NUMBER;
+        cachedContactInfo.formattedNumber = TEST_FORMATTED_NUMBER;
+        when(mContactInfoHelper.lookupNumber(anyString(), anyString()))
+                .thenReturn(cachedContactInfo);
+        ContactInfo contactInfo = getContactInfo(TEST_VALID_NUMBER, -1, TEST_COUNTRY_ISO);
+        assertEquals(TEST_VALID_NUMBER, contactInfo.number);
+        assertEquals(TEST_FORMATTED_NUMBER, contactInfo.name);
+    }
+
+    private ContactInfo getContactInfo(String number, int presentation, String countryIso) {
+        return mCallLogNotificationsHelper.getContactInfo(number, presentation, countryIso);
+    }
+}