diff --git a/docs/api.rst b/docs/api.rst
index 5e22814a..42f7c5a0 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -44,6 +44,13 @@ Request Sessions
 .. autoclass:: requests.adapters.HTTPAdapter
    :inherited-members:
 
+Authentication
+--------------
+
+.. autoclass:: requests.auth.AuthBase
+.. autoclass:: requests.auth.HTTPBasicAuth
+.. autoclass:: requests.auth.HTTPProxyAuth
+.. autoclass:: requests.auth.HTTPDigestAuth
 
 Exceptions
 ~~~~~~~~~~