diff --git a/internal/api/api.go b/internal/api/api.go
index 5bcfcda..6f6ca0c 100644
--- a/internal/api/api.go
+++ b/internal/api/api.go
@@ -752,10 +752,10 @@ func (a *API) buildFace(face string, routes []apiRoute, guard func(http.Handler)
 			h = callersOnly(rt.Callers, h)
 		}
 		if rt.Owner {
-			h = a.ownerOnly(rt.h)
+			h = a.ownerOnly(h)
 		}
 		if rt.Admin {
-			h = a.adminOnly(rt.h)
+			h = a.adminOnly(h)
 		}
 		// Default-deny setup-lockdown: wrap every authenticated route unless it
 		// explicitly opts out. The wrapper is nil-principal safe, so it is inert on
diff --git a/internal/api/route_tiers_test.go b/internal/api/route_tiers_test.go
new file mode 100644
index 0000000..7110c42
--- /dev/null
+++ b/internal/api/route_tiers_test.go
@@ -0,0 +1,41 @@
+package api
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+// Each tier a route sets is one more gate in front of its handler: a route marked
+// both Owner and Admin still refuses an admin who is not the owner.
+func TestBuildFaceStacksTierGates(t *testing.T) {
+	a := newTestAPI(newFakeRepo(), newFakeCluster())
+	ran := false
+	ok := func(w http.ResponseWriter, r *http.Request) { ran = true }
+	as := func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			p := &Principal{UserID: "u1", Role: r.Header.Get("X-Test-Role"), ViaAdminAccess: true, EmailVerified: true}
+			h.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), ctxKeyPrincipal, p)))
+		})
+	}
+	h := a.buildFace("external", []apiRoute{{Method: "GET", Pattern: "/api/v1/tiered", Owner: true, Admin: true, h: ok}}, as)
+
+	for _, c := range []struct {
+		role string
+		code int
+	}{
+		{"admin", http.StatusForbidden},
+		{"user", http.StatusForbidden},
+		{"owner", http.StatusOK},
+	} {
+		ran = false
+		r := httptest.NewRequest("GET", "/api/v1/tiered", nil)
+		r.Header.Set("X-Test-Role", c.role)
+		w := httptest.NewRecorder()
+		h.ServeHTTP(w, r)
+		if w.Code != c.code || ran != (c.code == http.StatusOK) {
+			t.Errorf("%s: status %d, handler ran %v; want %d", c.role, w.Code, ran, c.code)
+		}
+	}
+}