diff --git a/doc/install-guide/source/horizon-install.rst b/doc/install-guide/source/horizon-install.rst
index d1885cecc5..76cc6310c5 100644
--- a/doc/install-guide/source/horizon-install.rst
+++ b/doc/install-guide/source/horizon-install.rst
@@ -107,6 +107,8 @@ Install and configure components
 
         .. code-block:: ini
 
+           SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
+
            CACHES = {
                'default': {
                     'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
@@ -191,6 +193,8 @@ Install and configure components
 
         .. code-block:: ini
 
+           SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
+
            CACHES = {
                'default': {
                     'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
@@ -275,6 +279,8 @@ Install and configure components
 
         .. code-block:: ini
 
+           SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
+
            CACHES = {
                'default': {
                     'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',