diff --git a/chopper/lib/src/request.dart b/chopper/lib/src/request.dart
index 1441ef3d..0f134f7d 100644
--- a/chopper/lib/src/request.dart
+++ b/chopper/lib/src/request.dart
@@ -138,16 +138,23 @@ base class Request extends http.BaseRequest with EquatableMixin {
   @visibleForTesting
   http.Request toHttpRequest() {
     final http.Request request = http.Request(method, url)
-      ..followRedirects = followRedirects
-      ..headers.addAll(headers);
+      ..followRedirects = followRedirects;
 
-    if (body != null) {
+    if (body == null) {
+      request.headers.addAll(headers);
+    } else {
       if (body is String) {
-        request.body = body;
+        request
+          ..headers.addAll(headers)
+          ..body = body;
       } else if (body is List<int>) {
-        request.bodyBytes = body;
+        request
+          ..bodyBytes = body
+          ..headers.addAll(headers);
       } else if (body is Map<String, String>) {
-        request.bodyFields = body;
+        request
+          ..headers.addAll(headers)
+          ..bodyFields = body;
       } else {
         throw ArgumentError.value('$body', 'body');
       }
diff --git a/chopper/test/base_test.dart b/chopper/test/base_test.dart
index dee04012..f1e76dad 100644
--- a/chopper/test/base_test.dart
+++ b/chopper/test/base_test.dart
@@ -7,6 +7,7 @@ import 'package:chopper/chopper.dart';
 import 'package:http/http.dart' as http;
 import 'package:http/testing.dart';
 import 'package:test/test.dart';
+import 'package:transparent_image/transparent_image.dart';
 
 import 'test_service.dart';
 import 'test_service_variable.dart';
@@ -763,6 +764,25 @@ void main() {
       expect(request.bodyBytes, equals([1, 2, 3]));
     });
 
+    test('BodyBytes does not have charset header', () {
+      final request = Request(
+        HttpMethod.Post,
+        Uri.parse('https://foo/'),
+        Uri.parse(''),
+        headers: {
+          'authorization': 'Bearer fooBarBaz',
+          'x-foo': 'bar',
+        },
+        body: kTransparentImage,
+      ).toHttpRequest();
+
+      expect(request.headers['authorization'], equals('Bearer fooBarBaz'));
+      expect(request.headers['x-foo'], equals('bar'));
+      expect(request.headers['content-type'], isNull);
+      expect(request.headers['content-type'], isNot(contains('charset=')));
+      expect(request.bodyBytes, equals(kTransparentImage));
+    });
+
     test('BodyFields', () {
       final request = Request(
         HttpMethod.Post,