--- a/extensions.st	Fri Mar 25 16:46:12 2016 +0100
+++ b/extensions.st	Fri Mar 25 17:00:42 2016 +0100
@@ -2024,6 +2024,9 @@
 
     <resource: #programImage>
 
+    self isAbstract ifTrue:[
+        ^ #abstractWindowClassBrowserIcon
+    ].    
     ^ #windowClassBrowserIcon
 ! !