diff --git a/test/test_clientcert.py b/test/test_clientcert.py
index e054e8129..db1f8af91 100644
--- a/test/test_clientcert.py
+++ b/test/test_clientcert.py
@@ -39,7 +39,11 @@ class TestClientCert(unittest.TestCase):
 
     def test_check_clientcertificate(self):
         clientcertfn = os.path.join(TEST_DIR, 'testdata', 'clientcert', 'client.crt')
-        ydl = YoutubeDL({'logger': FakeLogger(), 'clientcertificate': clientcertfn})
+        ydl = YoutubeDL({'logger': FakeLogger(), 'clientcertificate': clientcertfn,
+            # Disable client-side validation of unacceptable self-signed testcert.pem
+            # The test is of a check on the server side, so unaffected
+            'nocheckcertificate': True,
+            })
         r = ydl.extract_info('https://127.0.0.1:%d/video.html' % self.port)
         self.assertEqual(r['entries'][0]['url'], 'https://127.0.0.1:%d/vid.mp4' % self.port)