diff --git a/modules/purchase_trade/stock.py b/modules/purchase_trade/stock.py
index ec94e37..44d08b0 100755
--- a/modules/purchase_trade/stock.py
+++ b/modules/purchase_trade/stock.py
@@ -710,14 +710,21 @@ class ShipmentIn(metaclass=PoolMeta):
         
         for sh in shipments:
             sh.result = "Email not sent"
-            attachment = None
+            attachment = []
             if sh.add_bl:
                 attachments = Attachment.search([
                     ('resource', '=', 'stock.shipment.in,' + str(sh.id)),
                 ])
                 if attachments:
-                    attachment = attachments[0]
-
+                    content_b64 = base64.b64encode(attachments[0].data).decode('ascii')
+                    attachment = [
+                            {
+                                "filename": attachments[0].name,
+                                "content": content_b64,
+                                "content_type": attachments[0].mimetype or "application/pdf"
+                            }
+                        ]
+            
             if sh.controller:
                 Contact = Pool().get('party.contact_mechanism')
                 contact = Contact.search(['party','=',sh.controller.id])
@@ -726,13 +733,7 @@ class ShipmentIn(metaclass=PoolMeta):
                         "to": [contact[0].value],
                         "subject": "Request for control",
                         "body": sh.html_to_text(sh.instructions),
-                        "attachments": [
-                            {
-                                "filename": attachment.name,
-                                "content": attachment.data,
-                                "content_type": "application/pdf"
-                            }
-                        ],
+                        "attachments": attachment,
                         "meta": {
                             "shipment": sh.bl_number,
                             "controller": sh.controller.id