Hi Pavel I have the impression that MCPackageLoader>>useChangeSetNamed: baseName during: aBlock "Use the named change set, or create one with the given name." | changeHolder oldChanges newChanges | changeHolder := (ChangeSet respondsTo: #newChanges:) ifTrue: [ChangeSet] ifFalse: [Smalltalk]. oldChanges := (ChangeSet respondsTo: #current) ifTrue: [ChangeSet current] ifFalse: [Smalltalk changes]. newChanges := (ChangeSorter changeSetNamed: baseName) ifNil: [ ChangeSet new name: baseName ]. changeHolder newChanges: newChanges. [aBlock value] ensure: [changeHolder newChanges: oldChanges]. should use Changes MCPackageLoader>>useChangeSetNamed: baseName during: aBlock "Use the named change set, or create one with the given name." | changeHolder oldChanges newChanges | changeHolder := (ChangeSet respondsTo: #newChanges:) ifTrue: [ChangeSet] ifFalse: [Smalltalk]. oldChanges := (ChangeSet respondsTo: #current) ifTrue: [ChangeSet current] ifFalse: [Smalltalk changes]. newChanges := (ChangesOrganizer changeSetNamed: baseName) ifNil: [ ChangeSet new name: baseName ]. changeHolder newChanges: newChanges. [aBlock value] ensure: [changeHolder newChanges: oldChanges]. It would be coherent not to really on UI (changeSorter) but on the domain objects (changeOrganizer). http://bugs.squeak.org/view.php?id= 4825 Stef