diff --git a/docs/conf.py b/docs/conf.py
index c29cb33..6705bdb 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -30,7 +30,8 @@ MOCK_MODULES = [
     "i3pystatus.pulseaudio.pulse",
     "notmuch",
     "requests",
-    "bs4"
+    "bs4",
+    "python-novaclient"
 ]
 
 for mod_name in MOCK_MODULES:
diff --git a/i3pystatus/openstack_vms.py b/i3pystatus/openstack_vms.py
index d8da803..52d7bad 100644
--- a/i3pystatus/openstack_vms.py
+++ b/i3pystatus/openstack_vms.py
@@ -9,6 +9,7 @@ class Openstack_vms(IntervalModule):
     """
     Displays the number of VMs in an openstack cluster in ACTIVE and
     non-ACTIVE states.
+    Requires: python-novaclient
     """
 
     settings = (