diff --git a/docs/hazmat/primitives/key-derivation-functions.rst b/docs/hazmat/primitives/key-derivation-functions.rst
index 11fbd4e..fdc540b 100644
--- a/docs/hazmat/primitives/key-derivation-functions.rst
+++ b/docs/hazmat/primitives/key-derivation-functions.rst
@@ -276,12 +276,16 @@
     :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised if the
         provided ``backend`` does not implement
         :class:`~cryptography.hazmat.backends.interfaces.HMACBackend`
+    :raises TypeError: This is raised if the provided ``info`` is a unicode object
 
     .. method:: derive(key_material)
 
         :param bytes key_material: The input key material.
         :return bytes: The derived key.
 
+        :raises TypeError: This is raised if the provided ``key_material`` is
+            a unicode object
+
         Derives a new key from the input key material by performing both the
         extract and expand operations.
 
@@ -300,6 +304,8 @@
                                                           :meth:`verify` is
                                                           called more than
                                                           once.
+        :raises TypeError: This is raised if the provided ``key_material`` is
+            a unicode object
 
         This checks whether deriving a new key from the supplied
         ``key_material`` generates the same key as the ``expected_key``, and