diff --git a/muk_utils/__manifest__.py b/muk_utils/__manifest__.py
index 6a7ce26..8031286 100644
--- a/muk_utils/__manifest__.py
+++ b/muk_utils/__manifest__.py
@@ -20,7 +20,7 @@
 {
     "name": "MuK Utils",
     "summary": """Utility Features""",
-    "version": '12.0.1.1.4',   
+    "version": '12.0.1.1.5',   
     "category": 'Extra Tools',   
     "license": "AGPL-3",
     "author": "MuK IT",
diff --git a/muk_utils/models/ir_attachment.py b/muk_utils/models/ir_attachment.py
index bd7e2c9..0a054a8 100644
--- a/muk_utils/models/ir_attachment.py
+++ b/muk_utils/models/ir_attachment.py
@@ -23,6 +23,7 @@ import mimetypes
 
 from odoo import api, models, _
 from odoo.exceptions import AccessError
+from odoo.tools.mimetypes import guess_mimetype
 
 _logger = logging.getLogger(__name__)
 
@@ -59,4 +60,15 @@ class Attachment(models.Model):
         storage = self._storage().upper()
         for index, attach in enumerate(self):
             _logger.info(_("Migrate Attachment %s of %s to %s") % (index + 1, record_count, storage))
-            attach.write({'datas': attach.datas})
+            attach.with_context(migration=True).write({'datas': attach.datas})
+            
+    #----------------------------------------------------------
+    # Read
+    #----------------------------------------------------------
+    
+    def _compute_mimetype(self, values):
+        if self.env.context.get('migration') and len(self) == 1:
+            return self.mimetype or 'application/octet-stream'
+        else:
+            return super(Attachment, self)._compute_mimetype(values)
+        
\ No newline at end of file