diff --git a/inventory/host_vars/undercloud01.cloud.fedoraproject.org b/inventory/host_vars/undercloud01.cloud.fedoraproject.org
index 31fe86f443..e00c54a4ad 100644
--- a/inventory/host_vars/undercloud01.cloud.fedoraproject.org
+++ b/inventory/host_vars/undercloud01.cloud.fedoraproject.org
@@ -1,5 +1,5 @@
 ---
-nm: 255.255.254.0
+nm: 255.255.255.0
 gw: 209.132.184.254
 dns: 8.8.8.8