diff --git a/environments/network-environment.yaml b/environments/network-environment.yaml
index 005310c71b..9f2c667b9b 100644
--- a/environments/network-environment.yaml
+++ b/environments/network-environment.yaml
@@ -22,7 +22,7 @@ parameter_defaults:
   TenantNetCidr: 172.16.0.0/24
   ExternalNetCidr: 10.0.0.0/24
   # CIDR subnet mask length for provisioning network
-  ControlPlaneSubnetCidr: 24
+  ControlPlaneSubnetCidr: '24'
   # Customize the IP ranges on each network to use for static IPs and VIPs
   InternalApiAllocationPools: [{'start': '172.17.0.10', 'end': '172.17.0.200'}]
   StorageAllocationPools: [{'start': '172.18.0.10', 'end': '172.18.0.200'}]