diff --git a/src/com/android/settings/network/telephony/NetworkProviderWifiCallingGroup.java b/src/com/android/settings/network/telephony/NetworkProviderWifiCallingGroup.java
index bc116001ebd..14bdd4123ab 100644
--- a/src/com/android/settings/network/telephony/NetworkProviderWifiCallingGroup.java
+++ b/src/com/android/settings/network/telephony/NetworkProviderWifiCallingGroup.java
@@ -285,7 +285,9 @@ public class NetworkProviderWifiCallingGroup extends
         }
 
         public void unregister() {
-            mTelephonyManager.unregisterTelephonyCallback(this);
+            if (mTelephonyManager != null) {
+                mTelephonyManager.unregisterTelephonyCallback(this);
+            }
         }
     }