diff --git a/docs/hazmat/primitives/cryptographic-hashes.rst b/docs/hazmat/primitives/cryptographic-hashes.rst
index 92f8fa3..312d7e6 100644
--- a/docs/hazmat/primitives/cryptographic-hashes.rst
+++ b/docs/hazmat/primitives/cryptographic-hashes.rst
@@ -34,6 +34,14 @@
     upgrading the hash algorithm you use over time. For more information, see
     `Lifetimes of cryptographic hash functions`_.
 
+    :param algorithm: A
+        :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+        provider such as those described in
+        :ref:`below <cryptographic-hash-algorithms>`.
+    :param backend: A
+        :class:`~cryptography.hazmat.bindings.interfaces.HashBackend`
+        provider.
+
     .. method:: update(data)
 
         :param bytes data: The bytes you wish to hash.
@@ -60,6 +68,8 @@
         :return bytes: The message digest as bytes.
 
 
+.. _cryptographic-hash-algorithms:
+
 SHA-1
 ~~~~~
 
diff --git a/docs/hazmat/primitives/hmac.rst b/docs/hazmat/primitives/hmac.rst
index 10db40e..db5e98d 100644
--- a/docs/hazmat/primitives/hmac.rst
+++ b/docs/hazmat/primitives/hmac.rst
@@ -34,6 +34,16 @@
         >>> h.finalize()
         '#F\xdaI\x8b"e\xc4\xf1\xbb\x9a\x8fc\xff\xf5\xdex.\xbc\xcd/+\x8a\x86\x1d\x84\'\xc3\xa6\x1d\xd8J'
 
+
+    :param key: Secret key as ``bytes``.
+    :param algorithm: A
+        :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+        provider such as those described in
+        :ref:`Cryptographic Hashes <cryptographic-hash-algorithms>`.
+    :param backend: A
+        :class:`~cryptography.hazmat.bindings.interfaces.HMACBackend`
+        provider.
+
     .. method:: update(msg)
 
         :param bytes msg: The bytes to hash and authenticate.
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst
index 76f68a1..f63ad90 100644
--- a/docs/hazmat/primitives/symmetric-encryption.rst
+++ b/docs/hazmat/primitives/symmetric-encryption.rst
@@ -44,8 +44,16 @@
         >>> decryptor.update(ct) + decryptor.finalize()
         'a secret message'
 
-    :param algorithms: One of the algorithms described below.
-    :param mode: One of the modes described below.
+    :param algorithms: A
+        :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm`
+        provider such as those described
+        :ref:`below <symmetric-encryption-algorithms>`.
+    :param mode: A :class:`~cryptography.hazmat.primitives.interfaces.Mode`
+        provider such as those described
+        :ref:`below <symmetric-encryption-modes>`.
+    :param backend: A
+        :class:`~cryptography.hazmat.bindings.interfaces.CipherBackend`
+        provider.
 
     .. method:: encryptor()
 
@@ -98,6 +106,8 @@
         :meth:`update` and :meth:`finalize` will raise
         :class:`~cryptography.exceptions.AlreadyFinalized`.
 
+.. _symmetric-encryption-algorithms:
+
 Algorithms
 ~~~~~~~~~~