diff --git a/module/install/config/form.php b/module/install/config/form.php
index eeb79e1d35..7f2362c962 100644
--- a/module/install/config/form.php
+++ b/module/install/config/form.php
@@ -15,3 +15,6 @@ $config->install->form->step2['dbPassword']  = array('type' => 'string', 'requir
 $config->install->form->step2['dbName']      = array('type' => 'string', 'required' => true);
 $config->install->form->step2['dbPrefix']    = array('type' => 'string', 'required' => true);
 $config->install->form->step2['clearDB']     = array('type' => 'int',    'required' => false, 'default' => 0);
+
+$config->install->form->step4 = array();
+$config->install->form->step4['mode'] = array('type' => 'string', 'required' => true);
diff --git a/module/install/control.php b/module/install/control.php
index 147100290e..b1862e48db 100644
--- a/module/install/control.php
+++ b/module/install/control.php
@@ -304,8 +304,9 @@ class install extends control
         {
             if(!isset($this->config->installed) || !$this->config->installed) return $this->send(array('result' => 'fail', 'message' => $this->lang->install->errorNotSaveConfig, 'load' => 'step3'));
 
-            $this->loadModel('setting')->setItem('system.common.global.mode', $this->post->mode);
-            $this->loadModel('custom')->disableFeaturesByMode($this->post->mode);
+            $mode = form::data()->get()->mode;
+            $this->loadModel('setting')->setItem('system.common.global.mode', $mode);
+            $this->loadModel('custom')->disableFeaturesByMode($mode);
             return $this->send(array('result' => 'success', 'load' => inlink('step5')));
         }