diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index d8953a2..d70f585 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -807,7 +807,8 @@
         mUi.onPause();
         mNetworkHandler.onPause();
         NfcHandler.unregister(mActivity);
-        mActivity.unregisterReceiver(mLowPowerReceiver);
+        if (mLowPowerReceiver != null)
+            mActivity.unregisterReceiver(mLowPowerReceiver);
     }
 
     @Override
@@ -884,7 +885,8 @@
         // Destroy all the tabs
         mTabControl.destroy();
         // Unregister receiver
-        mActivity.unregisterReceiver(mPowerChangeReceiver);
+        if (mPowerChangeReceiver != null)
+            mActivity.unregisterReceiver(mPowerChangeReceiver);
     }
 
     protected boolean isActivityPaused() {