--- a/WindowSensor.st	Fri May 11 09:24:25 2018 +0200
+++ b/WindowSensor.st	Fri May 11 09:24:54 2018 +0200
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 1993 by Claus Gittinger
               All Rights Reserved
@@ -2533,9 +2535,7 @@
      (by sending arbitrary events, which leads to a message send,
       when the target windowGroups process is rescheduled)."
 
-    anEvent timeStamp isNil ifTrue:[
-        anEvent timeStamp:Timestamp now.
-    ].
+    anEvent ensureTimeStamped.
 
     "/ inform all local and global eventListeners ?
     (self notifyEventListenersAbout:anEvent) ifTrue:[