1 files changed, 4 insertions, 2 deletions
diff --git a/tests/hazmat/primitives/test_hkdf.py b/tests/hazmat/primitives/test_hkdf.py
index b3d412c5..2e3c0c3d 100644
--- a/tests/hazmat/primitives/test_hkdf.py
+++ b/tests/hazmat/primitives/test_hkdf.py
@@ -18,11 +18,13 @@ import pytest
 import six
 
 from cryptography.exceptions import (
-    AlreadyFinalized, InvalidKey, UnsupportedAlgorithm
+    AlreadyFinalized, InvalidKey, _Reasons
 )
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.kdf.hkdf import HKDF
 
+from ...utils import raises_unsupported_algorithm
+
 
 @pytest.mark.hmac
 class TestHKDF(object):
@@ -152,5 +154,5 @@ class TestHKDF(object):
 def test_invalid_backend():
     pretend_backend = object()
 
-    with pytest.raises(UnsupportedAlgorithm):
+    with raises_unsupported_algorithm(_Reasons.BACKEND_MISSING_INTERFACE):
         HKDF(hashes.SHA256(), 16, None, None, pretend_backend)