Stef wrote

I do not think that it can be correct because ClassDecription defines it and it is under Object

I wasn’t precise enough. This is the current test. self assert: (Object allSubclasses select: [: each | (each class compiledMethodAt: #packages ifAbsent: [nil]) isNotNil]) isEmpty. It found the 5 (not 4, I missed one) extra implementations. Stephan