diff --git a/src/fibRoute.ts b/src/fibRoute.ts
index e4fa96e..b053d02 100644
--- a/src/fibRoute.ts
+++ b/src/fibRoute.ts
@@ -1,15 +1,16 @@
 // Endpoint for querying the fibonacci numbers
 
 import fibonacci from "./fib";
+import {Request, Response} from "express";
 
-export default (req, res) => {
+export default (req: Request, res: Response) => {
   const { num } = req.params;
 
-  const fibN = fibonacci(parseInt(num));
+  const fibN = fibonacci(parseInt(num)); 
   let result = `fibonacci(${num}) is ${fibN}`;
 
   if (fibN < 0) {
-    result = `fibonacci(${num}) is undefined`;
+    result = `fibonacci(${num}) is undefined`; //string
   }
 
   res.send(result);