diff --git a/plugins/css_bundler/src/middleware.ts b/plugins/css_bundler/src/middleware.ts
index 8065dc3..d78fd44 100644
--- a/plugins/css_bundler/src/middleware.ts
+++ b/plugins/css_bundler/src/middleware.ts
@@ -12,7 +12,7 @@ export function cssHandler(sourceDir: string): MiddlewareHandler {
 			if (
 				ctx.url.pathname.startsWith('/') && ctx.url.pathname.endsWith('.css')
 			) {
-				bundleCss(sourceDir, assetDir, ctx.url.pathname, ctx.config.dev)
+				await bundleCss(sourceDir, assetDir, ctx.url.pathname, ctx.config.dev)
 				const file = await Deno.readFile(join(assetDir, ctx.url.pathname))
 				return new Response(file, {
 					headers: {