diff --git a/tests/selenium/wdio.conf.js b/tests/selenium/wdio.conf.js
index 18d71e2d3..7eccde69b 100644
--- a/tests/selenium/wdio.conf.js
+++ b/tests/selenium/wdio.conf.js
@@ -2,10 +2,12 @@
 
 const { config } = require( 'wdio-mediawiki/wdio-defaults.conf.js' );
 
-exports.config = { ...config
+exports.config = { ...config,
 	// Override, or add to, the setting from wdio-mediawiki.
 	// Learn more at https://webdriver.io/docs/configurationfile/
 	//
 	// Example:
 	// logLevel: 'info',
+
+	maxInstances: 4
 };