diff --git a/modules/install/tpl/js/install.js b/modules/install/tpl/js/install.js
index 15bcc7389..ee565d81f 100644
--- a/modules/install/tpl/js/install.js
+++ b/modules/install/tpl/js/install.js
@@ -32,7 +32,7 @@ jQuery(function($){
 		var user_id_input = $("input[name='user_id']");
 		var email_input = $("input[name='email_address']");
 		email_input.on("blur", function() {
-			if (user_id_input.val() == "") {
+			if (user_id_input.val() == "" && email_input.val() != "") {
 				user_id_input.val(email_input.val().replace(/@.+$/g, "").replace(/[^a-zA-Z0-9_]/g, ""));
 			}
 		});