diff --git a/cocoscreator_projects/scripts/test/build-game.test.mjs b/cocoscreator_projects/scripts/test/build-game.test.mjs
index 0544076..25afcce 100644
--- a/cocoscreator_projects/scripts/test/build-game.test.mjs
+++ b/cocoscreator_projects/scripts/test/build-game.test.mjs
@@ -38,7 +38,7 @@ function makePng(w, h, rgb = [0, 0, 0]) {
 }
 
 const DEFAULT_BTN = makePng(64, 64, [1, 2, 3]);
-const SKINNED = makePng(64, 64, [1, 2, 3]);
+const SKINNED = makePng(64, 64, [9, 9, 9]);
 
 function put(dir, rel, content) {
   const p = join(dir, ...rel.split('/'));
@@ -82,6 +82,7 @@ test('buildGame 走通全流程：实体化 → 合成 → 调构建 → 写 bui
     const r = buildGame('demo', baseOpts(s, { runBuild: (dir, p) => calls.push([dir, p]) }));
 
     assert.ok(readFileSync(join(r.workspaceDir, 'assets', 'framework', 'ui', 'atlas-hall', 'btn.png')).equals(SKINNED));
+    assert.ok(readFileSync(join(s.frameworkSrc, 'ui', 'atlas-hall', 'btn.png')).equals(DEFAULT_BTN), '框架真源必须只读：合成只能发生在临时工作区');
     assert.equal(calls.length, 1);
     assert.equal(calls[0][0], r.workspaceDir);
     assert.equal(calls[0][1], 'web-mobile');