diff --git a/class/business/eCommerceSynchro.class.php b/class/business/eCommerceSynchro.class.php
index c8cd6eb..cad59ec 100644
--- a/class/business/eCommerceSynchro.class.php
+++ b/class/business/eCommerceSynchro.class.php
@@ -891,6 +891,7 @@ public function synchCategory($toNb=0)
                             $this->eCommerceMotherCategory->fk_category = $dBCategorie->id;
                             $this->eCommerceMotherCategory->fk_site = $this->eCommerceSite->id;
                             $this->eCommerceMotherCategory->remote_id = $categoryArray['parent_id'];
+                            $this->eCommerceMotherCategory->last_update = '';
 
                             // Create an entry to map importRootCategory in eCommerceCategory
                             $result = $this->eCommerceMotherCategory->create($this->user);
diff --git a/class/data/eCommerceCategory.class.php b/class/data/eCommerceCategory.class.php
index b140e81..dc15163 100644
--- a/class/data/eCommerceCategory.class.php
+++ b/class/data/eCommerceCategory.class.php
@@ -97,7 +97,7 @@ function create($user, $notrigger = 0)
         $sql.= " " . $this->db->escape($this->fk_site) . ",";
         $sql.= " " . (isset($this->remote_id) ? intval($this->remote_id) : 0) . ",";
         $sql.= " " . (isset($this->remote_parent_id) ? intval($this->remote_parent_id) : 0) . ",";
-        $sql.= " '" . $this->db->idate($this->last_update) . "'";
+        $sql.= " " . ($this->last_update > 0 ? "'" . $this->db->idate($this->last_update) . "'" : "NULL");
         $sql.= ")";
 
         $this->db->begin();