diff --git a/README.md b/README.md
index fdedcbac..d5cf3107 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ check whether the session is valid or not.
 There are two ways of serving this application under a base path:
 
 1. Let Express.js handle the routing by setting the `BASE_PATH` environment
-   variable to the sub-path, e.g. `/myapp`.
+   variable to the sub-path, e.g. `/myapp`. (without trailing slash)
 2. Use a reverse proxy or API gateway to strip the path prefix.
 
 The second approach is not always possible, especially when running the
diff --git a/src/index.ts b/src/index.ts
index 7557c1c6..6ac5a3c8 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -57,7 +57,7 @@ registerWelcomeRoute(router)
 registerErrorRoute(router)
 
 router.get("/", (req: Request, res: Response) => {
-  res.redirect(303, "welcome")
+  res.redirect(303, `${baseUrl}/welcome`)
 })
 
 registerStaticRoutes(router)