--- a/steps/signing.py
+++ b/steps/signing.py
@@ -31,18 +31,18 @@ class HTTPSVerifyingContextFactory(Conte
         ctx.set_verify(VERIFY_PEER | VERIFY_FAIL_IF_NO_PEER_CERT,
                        self.verifyHostname)
         ctx.set_options(OP_NO_SSLv2)
         return ctx
 
     def verifyHostname(self, connection, x509, errno, depth, preverifyOK):
         if preverifyOK:
             # Accept a hostname that matches the cert's commonName,
-            # or 'mozilla.com' for the releng_CA, or None for the old cert.
-            if x509.get_subject().commonName not in (self.hostname, "mozilla.com", None):
+            # or 'mozilla.com' for the releng_CA
+            if x509.get_subject().commonName not in (self.hostname, "mozilla.com"):
                 return False
         return preverifyOK
 
 
 class SigningServerAuthenication(StringDownload):
     current_attempt = 0
     stdio_log = None
     uri = None