diff --git a/cryptography/hazmat/backends/multibackend.py b/cryptography/hazmat/backends/multibackend.py
index 903bcce..86cded8 100644
--- a/cryptography/hazmat/backends/multibackend.py
+++ b/cryptography/hazmat/backends/multibackend.py
@@ -16,8 +16,8 @@
 from cryptography import utils
 from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
 from cryptography.hazmat.backends.interfaces import (
-    CipherBackend, DSABackend, HMACBackend, HashBackend,
-    PBKDF2HMACBackend, RSABackend
+    CipherBackend, DSABackend, HMACBackend, HashBackend, PBKDF2HMACBackend,
+    RSABackend
 )
 
 
diff --git a/docs/hazmat/primitives/mac/cmac.rst b/docs/hazmat/primitives/mac/cmac.rst
index c2a50cd..be35014 100644
--- a/docs/hazmat/primitives/mac/cmac.rst
+++ b/docs/hazmat/primitives/mac/cmac.rst
@@ -10,7 +10,7 @@
     import binascii
     key = binascii.unhexlify(b"0" * 32)
 
-Cipher-based message authentication codes (or CMACs) are a tool for calculating
+`Cipher-based message authentication codes`_ (or CMACs) are a tool for calculating
 message authentication codes using a block cipher coupled with a
 secret key. You can use an CMAC to verify both the integrity and authenticity
 of a message.
@@ -98,3 +98,6 @@
 
         :return bytes: The message authentication code as bytes.
         :raises cryptography.exceptions.AlreadyFinalized:
+
+
+.. _`Cipher-based message authentication codes`: https://en.wikipedia.org/wiki/CMAC