diff --git a/qfieldsync/core/cloud_api.py b/qfieldsync/core/cloud_api.py
index 70c5a1e3..d5dc28db 100644
--- a/qfieldsync/core/cloud_api.py
+++ b/qfieldsync/core/cloud_api.py
@@ -568,6 +568,9 @@ def cloud_upload_files(
 
         multi_part = QHttpMultiPart(QHttpMultiPart.FormDataType)
         multi_part.setParent(self)
+        multi_part.setBoundary(
+            b"boundary_.oOo.QFieldRoxAndYouKnowItDXMtCoIPQV84CAX3rDyv83393"
+        )
 
         # most of the time there is no other payload
         if payload is not None: