diff --git a/acme/acme/challenges_test.py b/acme/acme/challenges_test.py
index 6b277ac27..4f2d06167 100644
--- a/acme/acme/challenges_test.py
+++ b/acme/acme/challenges_test.py
@@ -264,9 +264,7 @@ class TLSSNI01ResponseTest(unittest.TestCase):
 
     def test_verify_bad_cert(self):
         self.assertFalse(self.response.verify_cert(
-            OpenSSL.crypto.load_certificate(
-                OpenSSL.crypto.FILETYPE_PEM,
-                test_util.load_vector('cert.pem'))))
+            test_util.load_cert('cert.pem')))
 
     def test_simple_verify_bad_key_authorization(self):
         key2 = jose.JWKRSA.load(test_util.load_vector('rsa256_key.pem'))