diff --git a/docs/wrap_cli.md b/docs/wrap_cli.md
index d48ae43..8e71e5c 100644
--- a/docs/wrap_cli.md
+++ b/docs/wrap_cli.md
@@ -54,7 +54,7 @@ $ python -m oneface.wrap_cli run example.yaml dash_app
 ```
 
 
-## Command insert
+## Flag insertion
 
 Extra string can insert to the actually executed command when the
 parameter is a `bool` type. It's useful when the command contains some
diff --git a/tests/test_dash.py b/tests/test_dash.py
index a914773..8e82924 100644
--- a/tests/test_dash.py
+++ b/tests/test_dash.py
@@ -23,7 +23,6 @@ def func(a: Arg[int, [-10, 10]] = 0,
     assert 0 == func.dash_app.layout.children[1].children[1].value
     assert 20 == func.dash_app.layout.children[2].children[1].value
 
-
     @app
     @one
     def func1(a: bool):
@@ -31,3 +30,11 @@ def func1(a: bool):
 
     assert 'True' == func1.dash_app.layout.children[1].children[1].value
 
+
+def test_download_type():
+    @app(result_type="download")
+    @one
+    def func(a: str):
+        return ""
+
+    assert func.dash_app is not None