diff --git a/email.errors/email/errors.py b/email.errors/email/errors.py
index 791239fa..d5444f6e 100644
--- a/email.errors/email/errors.py
+++ b/email.errors/email/errors.py
@@ -21,7 +21,7 @@ class BoundaryError(MessageParseError):
     """Couldn't find terminating boundary."""
 
 
-class MultipartConversionError(MessageError, TypeError):
+class MultipartConversionError(MessageError):#, TypeError):
     """Conversion to a multipart is prohibited."""