Index: urllib3-1.21.1/urllib3/util/ssl_.py
===================================================================
--- urllib3-1.21.1.orig/urllib3/util/ssl_.py
+++ urllib3-1.21.1/urllib3/util/ssl_.py
@@ -318,6 +318,8 @@ def ssl_wrap_socket(sock, keyfile=None,
     elif getattr(context, 'load_default_certs', None) is not None:
         # try to load OS default certs; works well on Windows (require Python3.4+)
         context.load_default_certs()
+    elif cert_reqs != ssl.CERT_NONE and hasattr(context, 'set_default_verify_paths'):
+        context.set_default_verify_paths()
 
     if certfile:
         context.load_cert_chain(certfile, keyfile)