diff --git a/module/common/model.php b/module/common/model.php
index d5619f4c28..b9f8b4c613 100644
--- a/module/common/model.php
+++ b/module/common/model.php
@@ -402,7 +402,11 @@ class commonModel extends model
         $this->config->system   = isset($config['system']) ? $config['system'] : array();
         $this->config->personal = isset($config[$account]) ? $config[$account] : array();
 
-        $this->commonTao->updateDBWebRoot($this->config->system);
+        /* Web root cannot be changed by api request. */
+        if(!$this->app->apiVersion)
+        {
+            $this->commonTao->updateDBWebRoot($this->config->system);
+        }
 
         /* Override the items defined in config/config.php and config/my.php. */
         if(isset($this->config->system->common))   $this->app->mergeConfig($this->config->system->common, 'common');