diff --git a/local/testing/testdata/transform-and-upload.py b/local/testing/testdata/transform-and-upload.py
index ff2a0c1518..c06cc75de4 100644
--- a/local/testing/testdata/transform-and-upload.py
+++ b/local/testing/testdata/transform-and-upload.py
@@ -463,10 +463,12 @@ def create_registry_asset(edc_upload_urls_, edc_asset_path_, edc_contract_defini
                     })
             print(name_at_manufacturer)
 
-            specific_asset_ids_temp.append({
+            manufacturerId = {
                 "key": "manufacturerId",
                 "value": tmp_data["bpnl"]
-            })
+            }
+            if manufacturerId not in specific_asset_ids_temp:
+                specific_asset_ids_temp.append(manufacturerId)
             if is_aas3:
                 keys = [{
                     "type": "GlobalReference",