--- a/gevent/ssl.py	2016-11-02 13:17:37.917401795 -0500
+++ b/gevent/newssl.py	2016-11-02 13:17:23.085401962 -0500
@@ -334,6 +334,8 @@ class SSLSocket(socket):
                         raise
                     sys.exc_clear()
                     self._wait(self._write_event, timeout_exc=_SSLErrorHandshakeTimeout)
+                elif ex.reason in ['SSLV3_ALERT_CERTIFICATE_EXPIRED', 'TLSV1_ALERT_UNKNOWN_CA']:
+                    return None
                 else:
                     raise

     def connect(self, addr):
         """Connects to remote ADDR, and then wraps the connection in