diff --git a/module/zahost/control.php b/module/zahost/control.php
index f016d936e2..c6b80f992a 100644
--- a/module/zahost/control.php
+++ b/module/zahost/control.php
@@ -303,7 +303,7 @@ class zahost extends control
      * @access public
      * @return void
      */
-    public function ajaxImageList($hostID, $templateID = null)
+    public function ajaxImageList($hostID, $templateID = 0)
     {
         $host      = $this->zahost->getById($hostID);
         $imageList = $this->zahost->getImageList($host, $templateID);
diff --git a/module/zahost/model.php b/module/zahost/model.php
index 006546b1b1..02b21154b9 100644
--- a/module/zahost/model.php
+++ b/module/zahost/model.php
@@ -175,10 +175,11 @@ class zahostModel extends model
      * Get image files from ZAgent server.
      *
      * @param  object $host
+     * @param  int    $templateID
      * @access public
      * @return array
      */
-    public function getImageList($host, $templateID = null)
+    public function getImageList($host, $templateID = 0)
     {
         $result = json_decode(commonModel::http("http://{$host->publicIP}:8086/api/v1/kvm/listTmpl?token={$host->secret}"));
         if(empty($result) || $result->code != 200)
@@ -197,7 +198,7 @@ class zahostModel extends model
             $imageList[] = array('name' => $image->name);
         }
 
-        /* templateID is not empty means editing template. */
+        /* Template ID is not empty means editing template. */
         if($templateID) foreach($usedImageList as $usedImage) $imageList[] = array('name' => $usedImage->imageName);
 
         return $imageList;