diff --git a/keystonemiddleware/auth_token/_cache.py b/keystonemiddleware/auth_token/_cache.py
index 4db934ae..b2e90362 100644
--- a/keystonemiddleware/auth_token/_cache.py
+++ b/keystonemiddleware/auth_token/_cache.py
@@ -89,6 +89,8 @@ class _MemcacheClientPool(object):
     """An advanced memcached client pool that is eventlet safe."""
 
     def __init__(self, memcache_servers, **kwargs):
+        # NOTE(sileht): This will import python-memcached, we don't want
+        # it as hard dependency, so lazy load it.
         from oslo_cache import _memcache_pool
         self._pool = _memcache_pool.MemcacheClientPool(memcache_servers,
                                                        **kwargs)
diff --git a/releasenotes/notes/bug-1737115-fa3d41e3d3cd7177.yaml b/releasenotes/notes/bug-1737115-fa3d41e3d3cd7177.yaml
new file mode 100644
index 00000000..bc7c8426
--- /dev/null
+++ b/releasenotes/notes/bug-1737115-fa3d41e3d3cd7177.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    [`bug 1737115 <https://bugs.launchpad.net/keystonemiddleware/+bug/1737115>`_]
+    Last release have accidentaly make python-memcached a hard dependency, this
+    have changed back to an optional one.