--- a/Tools__ObjectModuleInformation.st	Thu Apr 25 15:10:44 2013 +0200
+++ b/Tools__ObjectModuleInformation.st	Thu Apr 25 15:11:10 2013 +0200
@@ -1218,7 +1218,7 @@
     info := self selectedModuleInfo.
 
     name := info classNames detect:[:nm | self isExtensionName:nm].
-    packageID := (name copyWithoutLast:('_extensions' size)) asSymbol.
+    packageID := (name copyButLast:('_extensions' size)) asSymbol.
     methods := Smalltalk allExtensionsForPackage:packageID.
     (UserPreferences browserClass) browseMethods:methods title:('Extensions for ',packageID).
 !