diff --git a/phpgwapi/js/jsapi/egw_open.js b/phpgwapi/js/jsapi/egw_open.js
index 4a000c6201..337ef13d95 100644
--- a/phpgwapi/js/jsapi/egw_open.js
+++ b/phpgwapi/js/jsapi/egw_open.js
@@ -273,7 +273,7 @@ egw.extend('open', egw.MODULE_WND_LOCAL, function(_egw, _wnd) {
 			{
 				var w_h = _popup.split('x');
 				if (w_h[1] == 'egw_getWindowOuterHeight()') w_h[1] = egw_getWindowOuterHeight();
-				var popup_window = _wnd.egw_openWindowCentered2(url, _target, w_h[0], w_h[1], false, _target_app, true);
+				var popup_window = _wnd.egw_openWindowCentered2(url, _target || '_blank', w_h[0], w_h[1], false, _target_app, true);
 
 				// Remember which windows are open
 				egw().storeWindow(_target_app, popup_window);
diff --git a/phpgwapi/js/jsapi/jsapi.js b/phpgwapi/js/jsapi/jsapi.js
index addd24101c..ebef8ba2e2 100644
--- a/phpgwapi/js/jsapi/jsapi.js
+++ b/phpgwapi/js/jsapi/jsapi.js
@@ -445,7 +445,7 @@ function egw_openWindowCentered2(_url, _windowName, _width, _height, _status, _a
 
 	if (is_ie) _windowName = !_windowName ? '_blank' : _windowName.replace(/[^a-zA-Z0-9_]+/,'');	// IE fails, if name contains eg. a dash (-)
 
-	windowID = window.open(_url, _windowName, "width=" + _width + ",height=" + _height +
+	windowID = window.open(_url, _windowName || '_blank', "width=" + _width + ",height=" + _height +
 		",screenX=" + positionLeft + ",left=" + positionLeft + ",screenY=" + positionTop + ",top=" + positionTop +
 		",location=no,menubar=no,directories=no,toolbar=no,scrollbars=yes,resizable=yes,status="+_status);