diff --git a/src/fib.ts b/src/fib.ts
index 0d292e9..9a1095e 100644
--- a/src/fib.ts
+++ b/src/fib.ts
@@ -1,5 +1,5 @@
 // util function that computes the fibonacci numbers
-export default function fibonacci(n) {
+export default function fibonacci(n : number): number {
   if (n < 0) {
     return -1;
   } else if (n == 0) {
diff --git a/src/fibRoute.ts b/src/fibRoute.ts
index e4fa96e..3c17f34 100644
--- a/src/fibRoute.ts
+++ b/src/fibRoute.ts
@@ -1,8 +1,9 @@
 // Endpoint for querying the fibonacci numbers
 
+import { Request, Response } from "express";
 import fibonacci from "./fib";
 
-export default (req, res) => {
+export default (req: Request, res: Response) => {
   const { num } = req.params;
 
   const fibN = fibonacci(parseInt(num));