diff --git a/tests/hazmat/primitives/test_hkdf.py b/tests/hazmat/primitives/test_hkdf.py
index bee4217..598f09f 100644
--- a/tests/hazmat/primitives/test_hkdf.py
+++ b/tests/hazmat/primitives/test_hkdf.py
@@ -214,3 +214,6 @@
 
     with raises_unsupported_algorithm(_Reasons.BACKEND_MISSING_INTERFACE):
         HKDF(hashes.SHA256(), 16, None, None, pretend_backend)
+
+    with raises_unsupported_algorithm(_Reasons.BACKEND_MISSING_INTERFACE):
+        HKDFExpand(hashes.SHA256(), 16, None, pretend_backend)
diff --git a/tests/hazmat/primitives/utils.py b/tests/hazmat/primitives/utils.py
index 6c3f4c9..7cf5efd 100644
--- a/tests/hazmat/primitives/utils.py
+++ b/tests/hazmat/primitives/utils.py
@@ -26,7 +26,7 @@
 from cryptography.hazmat.primitives import hashes, hmac
 from cryptography.hazmat.primitives.asymmetric import rsa
 from cryptography.hazmat.primitives.ciphers import Cipher
-from cryptography.hazmat.primitives.kdf.hkdf import HKDF
+from cryptography.hazmat.primitives.kdf.hkdf import HKDF, HKDFExpand
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 
 from ...utils import load_vectors_from_file
@@ -347,10 +347,9 @@
 
 
 def hkdf_expand_test(backend, algorithm, params):
-    hkdf = HKDF(
+    hkdf = HKDFExpand(
         algorithm,
         int(params["l"]),
-        salt=binascii.unhexlify(params["salt"]) or None,
         info=binascii.unhexlify(params["info"]) or None,
         backend=backend
     )