diff --git a/website/demo.ts b/website/demo.ts
index cf7092b..c360e87 100644
--- a/website/demo.ts
+++ b/website/demo.ts
@@ -105,7 +105,7 @@ function renderRoutes() {
     return;
   }
 
-  const html = routes.map(route => {
+  const html = routes.map((route): string => {
     const bgColor = route.route_color ? `#${route.route_color}` : '#64748b';
     const textColor = route.route_text_color ? `#${route.route_text_color}` : getContrastColor(bgColor);
 
diff --git a/website/package.json b/website/package.json
index 6168362..a2b05a7 100644
--- a/website/package.json
+++ b/website/package.json
@@ -5,7 +5,8 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
-    "build": "vite build",
+    "build": "tsc --noEmit && vite build",
+    "typecheck": "tsc --noEmit",
     "preview": "vite preview"
   },
   "devDependencies": {