diff --git a/src/sample/conference/src/main/java/owt/sample/conference/MainActivity.java b/src/sample/conference/src/main/java/owt/sample/conference/MainActivity.java
index cfc901f1..cddad6d0 100644
--- a/src/sample/conference/src/main/java/owt/sample/conference/MainActivity.java
+++ b/src/sample/conference/src/main/java/owt/sample/conference/MainActivity.java
@@ -434,9 +434,9 @@ protected void onResume() {
 
     @Override
     protected void onDestroy() {
-        super.onDestroy();
+        conferenceClient.removeObserver(this);
 
-        System.exit(0);
+        super.onDestroy();
     }
 
     private void initConferenceClient() {