--- a/Lib/ssl.py
+++ b/Lib/ssl.py
@@ -537,7 +537,15 @@ class SSLSocket(socket):
             self._context = SSLContext(ssl_version)
             self._context.verify_mode = cert_reqs
             if ca_certs:
-                self._context.load_verify_locations(ca_certs)
+                capath = None
+                cafile = None
+                if os.path.isdir(ca_certs):
+                    capath = ca_certs
+                else:
+                    cafile = ca_certs
+                self._context.load_verify_locations(cafile=cafile, capath=capath)
+            elif cert_reqs != CERT_NONE:
+                self._context.set_default_verify_paths()
             if certfile:
                 self._context.load_cert_chain(certfile, keyfile)
             if npn_protocols: