diff --git a/test/main.ts b/test/main.ts
index 3218c8b..99a55ea 100644
--- a/test/main.ts
+++ b/test/main.ts
@@ -41,15 +41,16 @@ const getBook = (ctx: RouterContext<any>) => {
 
 const postBook = async (ctx: RouterContext<RouteParams>) => {
   const { request, response } = ctx;
+  response.type = 'application/json'
   if (request.hasBody) {
     const result: any = await request.body({
       contentTypes: {
         text: ["application/javascript"],
       },
-    });
-    const body: any = JSON.parse(result.value)
+    })
+    const body: {id:string} = await result.value
     const book: IBook | undefined = searchBookById(body.id)
-      if (!book) {
+    if (!book) {
       response.status = 200
       response.body = body
     } else {
diff --git a/test/test.json b/test/test.json
index 3cb1611..0751fc2 100644
--- a/test/test.json
+++ b/test/test.json
@@ -27,6 +27,6 @@
   },
   "url": "api-test:3000",
   "header": {
-    "Content-Type": "application/javascript"
+    "Content-Type": "application/json"
   }
 }