Added CMAC docs
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 71cd456..3ed4cfb 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -9,7 +9,7 @@
Backend implementations may provide a number of interfaces to support operations
such as :doc:`/hazmat/primitives/symmetric-encryption`,
:doc:`/hazmat/primitives/cryptographic-hashes`, and
-:doc:`/hazmat/primitives/hmac`.
+:doc:`/hazmat/primitives/mac/hmac`.
A specific ``backend`` may provide one or more of these interfaces.