diff --git a/calendar/js/et2_widget_event.js b/calendar/js/et2_widget_event.js
index 5b2fb5b8b7..62564e8dc1 100644
--- a/calendar/js/et2_widget_event.js
+++ b/calendar/js/et2_widget_event.js
@@ -104,7 +104,7 @@ var et2_calendar_event = et2_valueWidget.extend([et2_IDetachedDOM],
 		// Unregister, or we'll continue to be notified...
 		if(this.options.value)
 		{
-			var old_app_id = this.options.value.app_id ? this.options.value.app_id : this.options.value.id + (this.options.value.recur_type ? ':'+this.options.value.recur_date : '');
+			var old_app_id = this.options.value.id + (this.options.value.recur_type ? ':'+this.options.value.recur_date : '');
 			egw.dataUnregisterUID('calendar::'+old_app_id,false,this);
 		}
 	},
@@ -113,13 +113,13 @@ var et2_calendar_event = et2_valueWidget.extend([et2_IDetachedDOM],
 		// Un-register for updates
 		if(this.options.value)
 		{
-			var old_app_id = this.options.value.app_id ? this.options.value.app_id : this.options.value.id + (this.options.value.recur_type ? ':'+this.options.value.recur_date : '');
+			var old_app_id = this.options.value.id + (this.options.value.recur_type ? ':'+this.options.value.recur_date : '');
 			egw.dataUnregisterUID('calendar::'+old_app_id,false,this);
 		}
 		this.options.value = _value;
 
 		// Register for updates
-		var app_id = this.options.value.app_id ? this.options.value.app_id : this.options.value.id + (this.options.value.recur_type ? ':'+this.options.value.recur_date : '');
+		var app_id = this.options.value.id + (this.options.value.recur_type ? ':'+this.options.value.recur_date : '');
 		egw.dataRegisterUID('calendar::'+app_id, function(event) {
 			// Check for changing days in the grid view
 			if(this._parent && this._parent.instanceOf(et2_calendar_daycol) &&