diff --git a/pyinfra/rest.py b/pyinfra/rest.py
index 7f6ec3d..2bb799e 100644
--- a/pyinfra/rest.py
+++ b/pyinfra/rest.py
@@ -83,14 +83,13 @@ def post_partial(url, data: Iterable[bytes], metadata: dict):
     dispatch_http_method_left_and_forward_data_right = parallel_map(dispatch_methods, lift(identity))
     send_data_with_method_to_analyzer = starlift(send)
     extract_payload_from_responses = lift(methodcaller("json"))
-    flatten_buffered_payloads = flatten
 
     input_data_to_result_data = rcompose(
         pack_data_and_metadata_for_rest_transfer,
         dispatch_http_method_left_and_forward_data_right,
         send_data_with_method_to_analyzer,
         extract_payload_from_responses,
-        flatten_buffered_payloads,
+        flatten,  # analysis may be 1 -> 1 or 1 -> n, so flatten
     )
 
     return input_data_to_result_data(data)