--- a/ChangeSet.st	Fri Nov 14 14:27:42 2008 +0100
+++ b/ChangeSet.st	Tue Dec 02 14:02:52 2008 +0100
@@ -911,13 +911,17 @@
 !ChangeSet methodsFor:'private-accessing'!
 
 addChange:aChange
+    |changeClass|
+
     aChange timeOfChangeIfKnown isNil ifTrue:[
         aChange timeStamp:(Timestamp now).
     ].
 
     self add:aChange.
     changedClasses notNil ifTrue:[
-        changedClasses add:aChange changeClass.
+        (changeClass := aChange changeClass) notNil ifTrue:[      
+            changedClasses add:changeClass.
+        ].
     ].
     changeSelectors notNil ifTrue:[
         aChange isMethodChange ifTrue:[
@@ -2327,5 +2331,5 @@
 !ChangeSet class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic3/ChangeSet.st,v 1.154 2008-11-03 11:20:55 stefan Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic3/ChangeSet.st,v 1.155 2008-12-02 13:02:52 cg Exp $'
 ! !