diff --git a/extend/resources/receipt_attachments.py b/extend/resources/receipt_attachments.py
index 7a4add7..f41d889 100644
--- a/extend/resources/receipt_attachments.py
+++ b/extend/resources/receipt_attachments.py
@@ -39,5 +39,5 @@ async def create_receipt_attachment(
 
         return await self._request(
             method="post_multipart",
-            data={"transaction_id": transaction_id},
+            data={"transactionId": transaction_id},
             files={"file": file})