diff --git a/src/waypoint_gui.cpp b/src/waypoint_gui.cpp
--- a/src/waypoint_gui.cpp
+++ b/src/waypoint_gui.cpp
@@ -114,8 +114,14 @@ public:
 		}
 	}
 
-	virtual void OnInvalidateData(int data)
+	/**
+	 * Some data on this window has become invalid.
+	 * @param data Information about the changed data.
+	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
+	 */
+	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
 	{
+		if (!gui_scope) return;
 		/* You can only change your own waypoints */
 		this->SetWidgetDisabledState(WAYPVW_RENAME, !this->wp->IsInUse() || (this->wp->owner != _local_company && this->wp->owner != OWNER_NONE));
 		/* Disable the widget for waypoints with no use */