diff --git a/core/src/main/java/org/zstack/core/rest/RESTApiFacadeImpl.java b/core/src/main/java/org/zstack/core/rest/RESTApiFacadeImpl.java
index e9d9ead27f3..625e1fb6d8b 100755
--- a/core/src/main/java/org/zstack/core/rest/RESTApiFacadeImpl.java
+++ b/core/src/main/java/org/zstack/core/rest/RESTApiFacadeImpl.java
@@ -112,9 +112,7 @@ void init() throws ClassNotFoundException, InstantiationException, IllegalAccess
             }
         }
 
-        for (APIEvent e : boundEvents) {
-            bus.subscribeEvent(this, e);
-        }
+        bus.subscribeEvent(this, boundEvents.toArray(new APIEvent[boundEvents.size()]));
     }
 
     private static int initMaxRestResultLength() {