diff --git a/docs/setup.rst b/docs/setup.rst
--- a/docs/setup.rst
+++ b/docs/setup.rst
@@ -423,8 +423,12 @@ somehow pass the original information on
 configured to pick that information up and trust it.
 
 Kallithea will by default rely on its WSGI server to provide the IP of the
-client in the WSGI environment as ``REMOTE_ADDR``, but it can also
-get it from the ``X-Real-IP`` or ``X-Forwarded-For`` HTTP headers.
+client in the WSGI environment as ``REMOTE_ADDR``, but it can be configured to
+get it from an HTTP header that has been set by the proxy server. For
+example, if the proxy server puts the client IP in the ``X-Forwarded-For``
+HTTP header, set::
+
+    remote_addr_variable = HTTP_X_FORWARDED_FOR
 
 Kallithea will by default rely on finding the protocol (``http`` or ``https``)
 in the WSGI environment as ``wsgi.url_scheme``. If the proxy server puts