diff --git a/src/gui/widgets/timeline/timeline-body.hpp b/src/gui/widgets/timeline/timeline-body.hpp
index c248ca061..2f0d1ac68 100644
--- a/src/gui/widgets/timeline/timeline-body.hpp
+++ b/src/gui/widgets/timeline/timeline-body.hpp
@@ -102,6 +102,7 @@ protected:
   
   /**
    * An event handler for when the window must be redrawn.
+   * @todo looks like this was the main drawing hook, and happens to be discontinued in GTK3.   ///////////////////TICKET #937 : custom timeline widget draw function not invoked anymore
    */
   bool on_expose_event(GdkEventExpose* event);