--- a/UndefinedObject.st	Sat Nov 16 16:23:00 2019 +0100
+++ b/UndefinedObject.st	Sat Nov 16 22:34:07 2019 +0100
@@ -1,5 +1,3 @@
-"{ Encoding: utf8 }"
-
 "
  COPYRIGHT (c) 1988 by Claus Gittinger
 	      All Rights Reserved
@@ -156,6 +154,25 @@
 ! !
 
 
+!UndefinedObject methodsFor:'Compatibility-Squeak'!
+
+subclass:nameSymbol
+        instanceVariableNames:instVarNameString
+        classVariableNames:classVarNameString
+        package:packageName
+
+    "create a new class as a subclass of an existing class (the receiver).
+     The subclass will have indexed variables if the receiving-class has.
+     Squeak uses the category as package"
+
+    ^ self 
+        subclass:nameSymbol 
+        instanceVariableNames:instVarNameString 
+        classVariableNames:classVarNameString 
+        poolDictionaries:'' 
+        category:packageName
+! !
+
 
 
 !UndefinedObject methodsFor:'converting'!