diff --git a/src/gui/core/timer.cpp b/src/gui/core/timer.cpp
index 427ebeb54e72..00b03ddd2c1e 100644
--- a/src/gui/core/timer.cpp
+++ b/src/gui/core/timer.cpp
@@ -44,7 +44,13 @@ static std::map<std::size_t, timer>& get_timers()
 	static std::map<std::size_t, timer>* ptimers = new std::map<std::size_t, timer>();
 	return *ptimers;
 }
-/** The id of the event being executed, 0 if none. */
+/** 
+	The id of the event being executed, 0 if none.
+	NOTE: it is possible that multiple timers are executed at the same time
+	      if one of the timer starts an event loop for example if its handler
+		  shows a dialog. In that case code that relies on this breaks. This
+		  could probably fixed my making this a list/stack of ids.
+*/
 static std::size_t executing_id = 0;
 
 /** Did somebody try to remove the timer during its execution? */