diff --git a/cluster/openstack-heat/config-default.sh b/cluster/openstack-heat/config-default.sh
index 86ab7a3bcfa..c5c076e6056 100644
--- a/cluster/openstack-heat/config-default.sh
+++ b/cluster/openstack-heat/config-default.sh
@@ -37,6 +37,8 @@ EXTERNAL_NETWORK=${EXTERNAL_NETWORK:-public}
 
 LBAAS_VERSION=${LBAAS_VERSION:-}
 
+FIXED_NETWORK_CIDR=${FIXED_NETWORK_CIDR:-10.0.0.0/24}
+
 SWIFT_SERVER_URL=${SWIFT_SERVER_URL:-}
 
 # Flag indicates if new image must be created. If 'false' then image with IMAGE_ID will be used.