diff --git a/pvDataApp/misc/requester.h b/pvDataApp/misc/requester.h
index 064db95..ce04e8c 100644
--- a/pvDataApp/misc/requester.h
+++ b/pvDataApp/misc/requester.h
@@ -26,7 +26,7 @@ public:
     POINTER_DEFINITIONS(Requester);
     virtual ~Requester(){}
     virtual String getRequesterName() = 0;
-    virtual void message(String message,MessageType messageType) = 0;
+    virtual void message(String const & message,MessageType messageType) = 0;
 };
 
 }}