diff --git a/dev/api-gateway/gateway-kustomization.yaml b/dev/api-gateway/gateway-kustomization.yaml
index 11efcda..97aed43 100644
--- a/dev/api-gateway/gateway-kustomization.yaml
+++ b/dev/api-gateway/gateway-kustomization.yaml
@@ -13,6 +13,11 @@ spec:
   sourceRef:
     kind: GitRepository
     name: k8s-platform
+    # k8s-platform lives in flux-system: the templates are the platform's,
+    # this Kustomization is the team's. sourceRef resolves in the
+    # Kustomization's own namespace unless told otherwise, hence the
+    # explicit namespace rather than a copy of the source per domain.
+    namespace: flux-system
   path: ./dataplane-template
   prune: true
   postBuild:
diff --git a/dev/api-gateway/policies-kustomization.yaml b/dev/api-gateway/policies-kustomization.yaml
index 9211016..9fc6fb2 100644
--- a/dev/api-gateway/policies-kustomization.yaml
+++ b/dev/api-gateway/policies-kustomization.yaml
@@ -13,6 +13,11 @@ spec:
   sourceRef:
     kind: GitRepository
     name: k8s-platform
+    # k8s-platform lives in flux-system: the templates are the platform's,
+    # this Kustomization is the team's. sourceRef resolves in the
+    # Kustomization's own namespace unless told otherwise, hence the
+    # explicit namespace rather than a copy of the source per domain.
+    namespace: flux-system
   path: ./dataplane-globalpolicy-template
   prune: true
   postBuild: