diff --git a/src/async_impl/multipart.rs b/src/async_impl/multipart.rs
index ac4b8b981..df4dc1272 100644
--- a/src/async_impl/multipart.rs
+++ b/src/async_impl/multipart.rs
@@ -270,8 +270,9 @@ impl Part {
         let len = file.metadata().await.map(|m| m.len()).ok();
         let field = match len {
             Some(len) => Part::stream_with_length(file, len),
-            None => Part::stream(file)
-        }.mime(mime);
+            None => Part::stream(file),
+        }
+        .mime(mime);
 
         Ok(if let Some(file_name) = file_name {
             field.file_name(file_name)
diff --git a/tests/multipart.rs b/tests/multipart.rs
index bac6da314..78e170cbc 100644
--- a/tests/multipart.rs
+++ b/tests/multipart.rs
@@ -208,8 +208,11 @@ async fn async_impl_file_part() {
         async move {
             assert_eq!(req.method(), "POST");
             assert_eq!(req.headers()["content-type"], ct);
-            assert_eq!(req.headers()["transfer-encoding"], "chunked");
-
+            // files know their exact size
+            assert_eq!(
+                req.headers()["content-length"],
+                expected_body.len().to_string()
+            );
             let full = req.collect().await.unwrap().to_bytes();
 
             assert_eq!(full, expected_body.as_bytes());