diff --git a/assets/js/installation.js b/assets/js/installation.js
index 187b3e89..7a259116 100644
--- a/assets/js/installation.js
+++ b/assets/js/installation.js
@@ -51,7 +51,7 @@ $(function () {
                 $alert
                     .text('Easy!Appointments has been successfully installed!')
                     .addClass('alert-success')
-                    .show();
+                    .removeClass('hidden');
 
                 setTimeout(function () {
                     window.location.href = GlobalVariables.baseUrl + '/index.php/backend';
@@ -71,7 +71,7 @@ $(function () {
         try {
             $alert
                 .removeClass('alert-danger')
-                .hide();
+                .addClass('hidden');
             $('input').closest('.form-group').removeClass('has-error');
 
             // Check for empty fields.
@@ -116,7 +116,7 @@ $(function () {
             $alert
                 .addClass('alert-danger')
                 .text(error.message)
-                .show();
+                .removeClass('hidden');
 
             return false;
         }