diff --git a/index.test.js b/index.test.js
index 9a186e4..0b96a09 100644
--- a/index.test.js
+++ b/index.test.js
@@ -34,7 +34,7 @@ describe('extract domain', () => {
 
     it('should throw syntax error exception if the argument is not string nor array', () => {
         try {
-            extractDomain('{}');
+            extractDomain({});
         } catch (e) {
             assert.equal(e.name, 'TypeError');