diff --git a/services/surfaceflinger/MessageQueue.h b/services/surfaceflinger/MessageQueue.h
index 1004f4c..aed0aa9 100644
--- a/services/surfaceflinger/MessageQueue.h
+++ b/services/surfaceflinger/MessageQueue.h
@@ -69,7 +69,7 @@
         MessageQueue& mQueue;
         int32_t mEventMask;
     public:
-        Handler(MessageQueue& queue) : mQueue(queue), mEventMask(0) { }
+        explicit Handler(MessageQueue& queue) : mQueue(queue), mEventMask(0) { }
         virtual void handleMessage(const Message& message);
         void dispatchRefresh();
         void dispatchInvalidate();