diff --git a/packages/http-header-normalizer/index.d.ts b/packages/http-header-normalizer/index.d.ts
index a55779da4..9085c87ca 100644
--- a/packages/http-header-normalizer/index.d.ts
+++ b/packages/http-header-normalizer/index.d.ts
@@ -10,7 +10,7 @@ export interface Event {
   rawHeaders: Record<string, string>
 }
 
-declare function httpHeaderNormalizer(
+declare function httpHeaderNormalizer (
   options?: Options
 ): middy.MiddlewareObj<Event>