diff --git a/lcl/interfaces/gtk2/gtk2wscalendar.pp b/lcl/interfaces/gtk2/gtk2wscalendar.pp
index 67c4275fe6..a95a38c3d0 100644
--- a/lcl/interfaces/gtk2/gtk2wscalendar.pp
+++ b/lcl/interfaces/gtk2/gtk2wscalendar.pp
@@ -150,9 +150,14 @@ var
   CalendarCtrl: TCustomCalendar;
   CalendarWidget: PGtkCalendar;
 begin
+  // When the user drags a day number, the gtk2 starts a mouse capture.
+  // when the TCalendar is on a TDateEdit, the LCL destroys the widget while the
+  // gtk is still capturing. Result: The capture hangs.
+  // thaw it:
   CalendarCtrl:=TCustomCalendar(AWinControl);
   CalendarWidget:=GetCalendar(CalendarCtrl);
   gtk_calendar_thaw(CalendarWidget);
+
   inherited DestroyHandle(AWinControl);
 end;