diff --git a/environments/metrics/qdr-edge-only.yaml b/environments/metrics/qdr-edge-only.yaml
index 167732b66c..507862c5c2 100644
--- a/environments/metrics/qdr-edge-only.yaml
+++ b/environments/metrics/qdr-edge-only.yaml
@@ -8,7 +8,7 @@ resource_registry:
 
 parameter_defaults:
   ExtraConfig:
-    tripleo::profile::base::metrics::qdr::interior_mesh_nodes: []
+    tripleo::profile::base::metrics::qdr::interior_mesh_nodes: ''
     tripleo::profile::base::metrics::qdr::router_mode: edge
   BlockStorageExtraConfig:
     tripleo::profile::base::metrics::qdr::listener_addr: "%{hiera(hiera('block_storage_hostname_resolve_network'))}"