diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 050d69f..ce2f091 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -197,8 +197,7 @@
         :returns: ``True`` if the specified ``algorithm`` is supported for
             PBKDF2 HMAC by this backend, otherwise ``False``.
 
-    .. method:: derive_pbkdf2_hmac(self, algorithm, length, salt, iterations,
-                                   key_material)
+    .. method:: derive_pbkdf2_hmac(self, algorithm, length, salt, iterations, key_material)
 
         :param algorithm: An instance of a
             :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
diff --git a/docs/hazmat/primitives/key-derivation-functions.rst b/docs/hazmat/primitives/key-derivation-functions.rst
index f68b12c..6009687 100644
--- a/docs/hazmat/primitives/key-derivation-functions.rst
+++ b/docs/hazmat/primitives/key-derivation-functions.rst
@@ -211,9 +211,9 @@
 
     .. method:: verify(key_material, expected_key)
 
-        :param key_material bytes: The input key material. This is the same as
+        :param bytes key_material: The input key material. This is the same as
                                    ``key_material`` in :meth:`derive`.
-        :param expected_key bytes: The expected result of deriving a new key,
+        :param bytes expected_key: The expected result of deriving a new key,
                                    this is the same as the return value of
                                    :meth:`derive`.
         :raises cryptography.exceptions.InvalidKey: This is raised when the
@@ -304,9 +304,9 @@
 
     .. method:: verify(key_material, expected_key)
 
-        :param key_material bytes: The input key material. This is the same as
+        :param bytes key_material: The input key material. This is the same as
                                    ``key_material`` in :meth:`derive`.
-        :param expected_key bytes: The expected result of deriving a new key,
+        :param bytes expected_key: The expected result of deriving a new key,
                                    this is the same as the return value of
                                    :meth:`derive`.
         :raises cryptography.exceptions.InvalidKey: This is raised when the