diff --git a/A00_Common/design/design_shared.ts b/A00_Common/design/design_shared.ts
index 77d92cd9c..e4f1cbee4 100644
--- a/A00_Common/design/design_shared.ts
+++ b/A00_Common/design/design_shared.ts
@@ -421,7 +421,10 @@ export function confirmAndGo(shared: DesignPageShared, route: RoutePath): void {
   void moveStage(id, route, [
     {
       name: "설계 확정",
-      run: async () => (await alreadyConfirmed(id)) || saveSharedDesign(shared, true),
+      // 배수유역 낡음 = 확정 저장으로(서버 관 차례가 다시 셈) · 그 밖 이미 확정이면 저장 없이 감
+      run: async () =>
+        (!shared.profile?.side?.stale() && (await alreadyConfirmed(id))) ||
+        saveSharedDesign(shared, true),
       progress: () => designSaveProgress(id),
     },
   ]);
diff --git a/resources/tester/test_298_3_save_shape.py b/resources/tester/test_298_3_save_shape.py
index 2ad88e8c0..9071388f3 100644
--- a/resources/tester/test_298_3_save_shape.py
+++ b/resources/tester/test_298_3_save_shape.py
@@ -98,7 +98,8 @@ def test_3_고친_것_없고_단계_완료면_바로_이동():
     go = shared[shared.index("export function confirmAndGo(") :]
     go = go[: go.index("\n}\n")]
     # 잠금판 한 단계 — 확정됐으면 저장 없이 이동(520-4 moveStage)
-    assert "run: async () => (await alreadyConfirmed(id)) || saveSharedDesign(shared, true)," in go
+    assert "(!shared.profile?.side?.stale() && (await alreadyConfirmed(id))) ||" in go
+    assert "saveSharedDesign(shared, true)," in go
     # 줄 세움 = [저장] · 확정 한 곳
     assert "await queueDesignSave(shared.projectId, confirm, () =>" in shared
     assert "saveOnce(shared, confirm, moved)," in shared