diff --git a/setup.js b/setup.js
index 71a2129..0c6fac5 100644
--- a/setup.js
+++ b/setup.js
@@ -1,18 +1,13 @@
+const expect = require('chai').expect;
+
 // setup JSDOM
 process.stdout.write('Setting up JSDOM...');
 require('jsdom-global')();
 
-// See https://github.com/vuejs/vue/issues/9698
-global.performance = window.performance;
-
 // See https://github.com/vuejs/vue-test-utils/issues/936#issuecomment-415386167
 window.Date = Date;
 
-if (window && window.document) {
-  process.stdout.write('OK.\r\n')
-} else {
-  process.stdout.write('Not OK.\r\n')
-}
+process.stdout.write(window && window.document ? 'OK.\r\n' : 'Not OK.\r\n');
 
-// make expect available globally
-global.expect = require('expect');
+// make chai.expect available globally
+global.expect = expect;