diff --git a/phpgwapi/js/egw_json.js b/phpgwapi/js/egw_json.js
index 4ff51497a4..e92a54ba8c 100644
--- a/phpgwapi/js/egw_json.js
+++ b/phpgwapi/js/egw_json.js
@@ -24,9 +24,9 @@ function egw_json_request(_menuaction, _parameters)
 	this.sender = null;
 	this.callback = null;
 	this.alertHandler = this.alertFunc;
-	if (document.alertHandler)
+	if (window.egw_alertHandler)
 	{
-		this.alertHandler = document.alertHandler;
+		this.alertHandler = window.egw_alertHandler;
 	}
 }