Hi, I was debugging some test failures and it turns out that my code defines an ASN1IntegerType and the Cryptography package (a dependency of MongoTalk which is loaded into my code) has such a class as well. Thanks to Epicea I could see which package added the method but now I have no idea how to resolve the problem. Mongotalk needs PBKDF2 for modern authentication... Could Cryptography use "ASN1-Model"[1] instead? This is a rather complete[2] ASN1 implementation and used in production for some years. Could the classes be prefixed? If not how can I instruct Metacello to not load a certain package? holger [1] http://smalltalkhub.com/#!/~NorbertHartl/ASN1/source [2] Rather complete parser for ASN1 files but only encoding/decoding for DER/BER (none of the modern ones like aper/uper