diff --git a/clusters/titan.lan.huizinga.dev/apps.yaml b/clusters/titan.lan.huizinga.dev/apps.yaml
index 420fc53..c4f7ab2 100644
--- a/clusters/titan.lan.huizinga.dev/apps.yaml
+++ b/clusters/titan.lan.huizinga.dev/apps.yaml
@@ -16,11 +16,9 @@ spec:
     kind: GitRepository
     name: flux-system
   postBuild:
-    substitute:
-      domain: staging.huizinga.dev
-      # Specifically for authelia
-      subdomain: .staging
-      topdomain: huizinga.dev
+    substituteFrom:
+      - kind: ConfigMap
+        name: domain-vars
   path: ./apps
   prune: true
   wait: true
diff --git a/clusters/titan.lan.huizinga.dev/config-map-domain-vars.yaml b/clusters/titan.lan.huizinga.dev/config-map-domain-vars.yaml
new file mode 100644
index 0000000..3941578
--- /dev/null
+++ b/clusters/titan.lan.huizinga.dev/config-map-domain-vars.yaml
@@ -0,0 +1,10 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: domain-vars
+  namespace: flux-system
+data:
+  domain: staging.huizinga.dev
+  # Specifically for authelia
+  subdomain: .staging
+  topdomain: huizinga.dev
diff --git a/clusters/titan.lan.huizinga.dev/infrastructure.yaml b/clusters/titan.lan.huizinga.dev/infrastructure.yaml
index 5d6b333..06e914c 100644
--- a/clusters/titan.lan.huizinga.dev/infrastructure.yaml
+++ b/clusters/titan.lan.huizinga.dev/infrastructure.yaml
@@ -17,11 +17,9 @@ spec:
     kind: GitRepository
     name: flux-system
   postBuild:
-    substitute:
-      domain: staging.huizinga.dev
-      # Specifically for authelia
-      subdomain: .staging
-      topdomain: huizinga.dev
+    substituteFrom:
+      - kind: ConfigMap
+        name: domain-vars
   path: ./infrastructure/controllers
   prune: true
   wait: true