diff --git a/Lib/test/test_smtpnet.py b/Lib/test/test_smtpnet.py
index 7d0fa98..86224ef 100644
--- a/Lib/test/test_smtpnet.py
+++ b/Lib/test/test_smtpnet.py
@@ -18,7 +18,13 @@
         support.get_attribute(smtplib, 'SMTP_SSL')
         with support.transient_internet(self.testServer):
             server = smtplib.SMTP(self.testServer, self.remotePort)
-            server.starttls(context=self.context)
+            try:
+                server.starttls(context=self.context)
+            except smtplib.SMTPException as e:
+                if e.args[0] == 'STARTTLS extension not supported by server.':
+                    unittest.skip(e.args[0])
+                else:
+                    raise
             server.ehlo()
             server.quit()