diff --git a/services/java/com/android/server/BluetoothManagerService.java b/services/java/com/android/server/BluetoothManagerService.java
index d2d5280..546324a 100644
--- a/services/java/com/android/server/BluetoothManagerService.java
+++ b/services/java/com/android/server/BluetoothManagerService.java
@@ -766,13 +766,17 @@
                 case MESSAGE_REGISTER_STATE_CHANGE_CALLBACK:
                 {
                     IBluetoothStateChangeCallback callback = (IBluetoothStateChangeCallback) msg.obj;
-                    mStateChangeCallbacks.register(callback);
+                    if (callback != null) {
+                        mStateChangeCallbacks.register(callback);
+                    }
                     break;
                 }
                 case MESSAGE_UNREGISTER_STATE_CHANGE_CALLBACK:
                 {
                     IBluetoothStateChangeCallback callback = (IBluetoothStateChangeCallback) msg.obj;
-                    mStateChangeCallbacks.unregister(callback);
+                    if (callback != null) {
+                        mStateChangeCallbacks.unregister(callback);
+                    }
                     break;
                 }
                 case MESSAGE_BLUETOOTH_SERVICE_CONNECTED: