diff --git a/tests/hazmat/primitives/test_hmac.py b/tests/hazmat/primitives/test_hmac.py
index bbaabb2..a44838c 100644
--- a/tests/hazmat/primitives/test_hmac.py
+++ b/tests/hazmat/primitives/test_hmac.py
@@ -47,4 +47,4 @@
 
     def test_hmac_algorithm_instance(self):
         with pytest.raises(TypeError):
-            hmac.HMAC(hashes.SHA1)
+            hmac.HMAC(b"key", hashes.SHA1)