diff --git a/dpdispatcher/contexts/ssh_context.py b/dpdispatcher/contexts/ssh_context.py
index 5d9bb1de..aed7b299 100644
--- a/dpdispatcher/contexts/ssh_context.py
+++ b/dpdispatcher/contexts/ssh_context.py
@@ -636,9 +636,9 @@ def upload(
                 ).as_posix()
                 sha256_list.append(f"{sha256}  {jj_rel}")
             # write to remote
-            sha256_file = os.path.join(
-                self.remote_root, ".tmp.sha256." + str(uuid.uuid4())
-            )
+            sha256_file = pathlib.PurePath(
+                os.path.join(self.remote_root, ".tmp.sha256." + str(uuid.uuid4()))
+            ).as_posix()
             self.write_file(sha256_file, "\n".join(sha256_list))
             # check sha256
             # `:` means pass: https://stackoverflow.com/a/2421592/9567349