diff -r 7c7938425fb3 -r a6697947e277 src/Pure/GUI/gui.scala
--- a/src/Pure/GUI/gui.scala	Sat Nov 30 21:17:53 2013 +0100
+++ b/src/Pure/GUI/gui.scala	Sat Nov 30 22:56:20 2013 +0100
@@ -127,7 +127,7 @@
   /* icon */
 
   def isabelle_icon(): ImageIcon =
-    new ImageIcon(getClass.getClassLoader.getResource("isabelle/isabelle.gif"))
+    new ImageIcon(getClass.getClassLoader.getResource("isabelle/isabelle-icon.gif"))
 
   def isabelle_image(): Image = isabelle_icon().getImage