diff --git a/modules/web_shop_shopify/sale.py b/modules/web_shop_shopify/sale.py
index ddf94981c4..2d57c8e54b 100644
--- a/modules/web_shop_shopify/sale.py
+++ b/modules/web_shop_shopify/sale.py
@@ -556,6 +556,7 @@ class Sale(IdentifierMixin, metaclass=PoolMeta):
         """
         pool = Pool()
         Payment = pool.get('account.payment')
+        self.lock()
         with self.web_shop.shopify_session():
             for shipment in self.shipments:
                 fulfillment = shipment.get_shopify(self)
@@ -578,6 +579,9 @@ class Sale(IdentifierMixin, metaclass=PoolMeta):
                     shipment.set_shopify_identifier(
                         self, gid2id(fulfillment['id']))
                     Transaction().commit()
+                    # Start a new transaction as commit release the lock
+                    self.__class__.__queue__._process_shopify(self)
+                    return
                 elif shipment.state == 'cancelled':
                     fulfillment_id = shipment.get_shopify_identifier(self)
                     if fulfillment_id: