diff --git a/overcloud.j2.yaml b/overcloud.j2.yaml
index 94abac2d6f..4564e28a61 100644
--- a/overcloud.j2.yaml
+++ b/overcloud.j2.yaml
@@ -1197,7 +1197,7 @@ resources:
 {%- for role in roles %}
         {{role.name}}:
           yaql:
-            expression: list($.data.where($ != null))
+            expression: list($.data.where($ != null)).flatten()
             data:
               - {get_attr: [Networks, net_attributes_map, ctlplane, subnets, {get_param: {{role.name}}ControlPlaneSubnet}, gateway_ip]}
     {%- for network in networks %}