Changed cmac_supported() to cmac_algorithm_supported()
diff --git a/cryptography/hazmat/backends/interfaces.py b/cryptography/hazmat/backends/interfaces.py
index 4137b53..92413d8 100644
--- a/cryptography/hazmat/backends/interfaces.py
+++ b/cryptography/hazmat/backends/interfaces.py
@@ -147,9 +147,9 @@
 @six.add_metaclass(abc.ABCMeta)
 class CMACBackend(object):
     @abc.abstractmethod
-    def cmac_supported(self):
+    def cmac_algorithm_supported(self, algorithm):
         """
-        Returns True if the backend supports CMAC
+        Returns True if the block cipher is supported for CMAC by this backend
         """
 
     @abc.abstractmethod
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 546aa76..394d060 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -327,9 +327,12 @@
 
     A backend with methods for using CMAC
 
-    .. method:: cmac_supported()
+    .. method:: cmac_algorithm_supported(algorithm)
 
-        :return: True if CMAC is supported by the backend. False if otherwise.
+        :param algorithm: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.BlockCipherAlgorithm`
+            provider.
+        :return: Returns True if the block cipher is supported for CMAC by this backend
 
     .. method:: create_cmac_ctx(algorithm)