diff --git a/.changeset/serious-bottles-wave.md b/.changeset/serious-bottles-wave.md
new file mode 100644
index 000000000000..da3113c8abe9
--- /dev/null
+++ b/.changeset/serious-bottles-wave.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+[fix] handle root route for split config
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 6ce0637d4794..d45126e3d738 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -227,7 +227,7 @@ export default function ({ external = [], edge, split } = {}) {
 
 							const src = `${sliced_pattern}(?:/__data.json)?$`; // TODO adding /__data.json is a temporary workaround — those endpoints should be treated as distinct routes
 
-							await generate_function(route.id || 'index', src, entry.generateManifest);
+							await generate_function(route.id.slice(1) || 'index', src, entry.generateManifest);
 						}
 					};
 				});