diff --git a/ocaml/database/block_device_io.ml b/ocaml/database/block_device_io.ml
index 738c181605..048c5db801 100644
--- a/ocaml/database/block_device_io.ml
+++ b/ocaml/database/block_device_io.ml
@@ -324,7 +324,7 @@ let transfer_data_from_sock_to_fd sock dest_fd available_space target_response_t
         (* Otherwise write it *)
         Unixext.time_limited_write dest_fd len chunk target_response_time;
         total_length := !total_length + len
-      ) data_client
+      ) ~block_size:16384 data_client
     )
     (fun () -> 
       (* Close the connection *)