diff --git a/pymisp/api.py b/pymisp/api.py
index cd2a74a..082abe8 100644
--- a/pymisp/api.py
+++ b/pymisp/api.py
@@ -3492,8 +3492,10 @@ class PyMISP:
         """
         uuid = get_uuid_or_id_from_abstract_misp(misp_entity)
         if isinstance(tag, MISPTag):
-            tag = tag.name
-        to_post = {'uuid': uuid, 'tag': tag, 'local': local}
+            tag_name = tag.name if 'name' in tag else ""
+        else:
+            tag_name = tag
+        to_post = {'uuid': uuid, 'tag': tag_name, 'local': local}
         response = self._prepare_request('POST', 'tags/attachTagToObject', data=to_post)
         return self._check_json_response(response)
 
@@ -3505,8 +3507,7 @@ class PyMISP:
         """
         uuid = get_uuid_or_id_from_abstract_misp(misp_entity)
         if isinstance(tag, MISPTag):
-            if 'name' in tag:
-                tag_name = tag.name
+            tag_name = tag.name if 'name' in tag else ""
         else:
             tag_name = tag
         to_post = {'uuid': uuid, 'tag': tag_name}