diff --git a/environments/network-environment-v6.j2.yaml b/environments/network-environment-v6.j2.yaml
index 95e6e0fd36..a95461af2b 100644
--- a/environments/network-environment-v6.j2.yaml
+++ b/environments/network-environment-v6.j2.yaml
@@ -37,16 +37,20 @@ parameter_defaults:
   # Leave room if the external network is also used for floating IPs
 {%-         endif %}
   {{network.name}}AllocationPools: {{network.ipv6_allocation_pools}}
+{%-     if network.gateway_ipv6|default(false) %}
+  # Gateway router for routable networks
+  {{network.name}}InterfaceDefaultRoute: '{{network.gateway_ipv6}}'
+{%-     endif %}
 {%-     else %}
   # Tenant tunneling network is IPv4 until IPv6 is fully supported
   # Customize the IP subnets to match the local environment
   {{network.name}}NetCidr: '{{network.ip_subnet}}'
   # Customize the IP range to use for static IPs and VIPs
   {{network.name}}AllocationPools: {{network.allocation_pools}}
-{%-     endif %}
-{%-     if network.gateway_ipv6|default(false) %}
+{%-     if network.gateway_ip|default(false) %}
   # Gateway router for routable networks
-  {{network.name}}InterfaceDefaultRoute: '{{network.gateway_ipv6}}'
+  {{network.name}}InterfaceDefaultRoute: '{{network.gateway_ip}}'
+{%-     endif %}
 {%-     endif %}
 {%-     if network.vlan is defined %}
   # Customize the VLAN ID to match the local environment