diff --git a/src/android/RedLightScan.java b/src/android/RedLightScan.java
index dffe554..cc6eb44 100644
--- a/src/android/RedLightScan.java
+++ b/src/android/RedLightScan.java
@@ -24,6 +24,7 @@ public class RedLightScan extends CordovaPlugin {
     private static String TAG = RedLightScan.class.getSimpleName();
     private ScanUtil scanUtil;
     private CallbackContext callbackContext;
+    private boolean receiverRegisted = false;
 
     // BroadcastReceiver to receiver scan data
     private BroadcastReceiver receiver = new BroadcastReceiver() {
@@ -88,11 +89,15 @@ public class RedLightScan extends CordovaPlugin {
         IntentFilter filter = new IntentFilter();
         filter.addAction("com.rfid.SCAN");
         webView.getContext().registerReceiver(receiver, filter);
+        this.receiverRegisted = true;
+        Log.d(TAG, "RedLightScan receiver registed");
     }
 
     private void unregisterReceiver() {
-        if (receiver != null) {
+        if (this.receiverRegisted) {
             webView.getContext().unregisterReceiver(receiver);
+            this.receiverRegisted = false;
+            Log.d(TAG, "RedLightScan receiver unregisted");
         }
     }