diff --git a/app/main.py b/app/main.py
index 902c1b2..6a2e044 100644
--- a/app/main.py
+++ b/app/main.py
@@ -148,7 +148,9 @@ app.mount(
 class _NoCacheHTMLStaticFiles(StaticFiles):
     async def get_response(self, path: str, scope):
         resp = await super().get_response(path, scope)
-        if path.endswith(".html"):
+        # 按响应 content-type 判定,而非请求 path:html=True 时目录式 URL(/h5/x/)
+        # 经 Starlette 内部回落到 index.html,此刻 path 仍是 "x/"(不带 .html)。
+        if resp.headers.get("content-type", "").startswith("text/html"):
             resp.headers["Cache-Control"] = "no-cache"
         return resp
 
diff --git a/tests/test_h5_hosting.py b/tests/test_h5_hosting.py
index 76eeff4..2a5d09b 100644
--- a/tests/test_h5_hosting.py
+++ b/tests/test_h5_hosting.py
@@ -12,3 +12,10 @@ def test_h5_html_no_cache(client) -> None:
     resp = client.get("/h5/mine/index.html")
     assert resp.status_code == 200
     assert resp.headers.get("cache-control") == "no-cache"
+
+
+def test_h5_html_no_cache_via_dir_url(client) -> None:
+    # 目录式 URL(WebView 规范入口)经 html=True 回落 index.html,也必须带 no-cache
+    resp = client.get("/h5/mine/")
+    assert resp.status_code == 200
+    assert resp.headers.get("cache-control") == "no-cache"