diff --git a/aiohttp_pydantic/oas/__init__.py b/aiohttp_pydantic/oas/__init__.py
index d269f94..fbc1f90 100644
--- a/aiohttp_pydantic/oas/__init__.py
+++ b/aiohttp_pydantic/oas/__init__.py
@@ -14,12 +14,13 @@ def setup(
     url_prefix: str = "/oas",
     enable: bool = True,
     version_spec: Optional[str] = None,
-    title_spec: Optional[str] = None
+    title_spec: Optional[str] = None,
+    custom_template: Optional[jinja2.Template] = None
 ):
     if enable:
         oas_app = web.Application()
         oas_app["apps to expose"] = tuple(apps_to_expose) or (app,)
-        oas_app["index template"] = jinja2.Template(
+        oas_app["index template"] = custom_template or jinja2.Template(
             resources.read_text("aiohttp_pydantic.oas", "index.j2")
         )
         oas_app["version_spec"] = version_spec
diff --git a/aiohttp_pydantic/oas/index.j2 b/aiohttp_pydantic/oas/index.j2
index fe18e0c..c1b0745 100644
--- a/aiohttp_pydantic/oas/index.j2
+++ b/aiohttp_pydantic/oas/index.j2
@@ -5,7 +5,7 @@
     <meta charset="UTF-8">
     <title>{{ title | default('Swagger UI') }}</title>
     <link rel="stylesheet" type="text/css" href="{{ static_url | trim('/') }}/swagger-ui.css" />
-    <link rel="stylesheet" type="text/css" href="index.css" />
+    <link rel="stylesheet" type="text/css" href="{{ static_url | trim('/') }}/index.css" />
     <link rel="icon" type="image/png" href="{{ static_url | trim('/') }}/favicon-32x32.png" sizes="32x32" />
     <link rel="icon" type="image/png" href="{{ static_url | trim('/') }}/favicon-16x16.png" sizes="16x16" />
   </head>