diff --git a/caesar/caesar.spec.js b/caesar/caesar.spec.js
index 3ff9a35..2322455 100644
--- a/caesar/caesar.spec.js
+++ b/caesar/caesar.spec.js
@@ -1,4 +1,4 @@
-const caesar = require('./caesar')
+const caesar = require('./caesar.js')
 
 test('works with single letters', () => {
   expect(caesar('A', 1)).toBe('B');