diff --git a/lib/src/_internal/web_utils.dart b/lib/src/_internal/web_utils.dart
index f8062b8..46f8b63 100644
--- a/lib/src/_internal/web_utils.dart
+++ b/lib/src/_internal/web_utils.dart
@@ -20,6 +20,8 @@ extension type Headers._(JSObject _) implements web.Headers {
   external ArrayIterator keys();
   external ArrayIterator values();
 
+  factory Headers.fromHost(web.Headers host) => Headers._(host);
+
   factory Headers.fromEntries(Iterable<MapEntry<String, String>> entries) {
     final headers = Headers();
     for (final MapEntry(key: name, :value) in entries) {
diff --git a/lib/src/fetch/headers.js.dart b/lib/src/fetch/headers.js.dart
index 5e557bd..93c34fd 100644
--- a/lib/src/fetch/headers.js.dart
+++ b/lib/src/fetch/headers.js.dart
@@ -102,3 +102,6 @@ class Headers
     }
   }
 }
+
+Headers headersFromHost(dom.Headers host) =>
+    Headers._(web.Headers.fromHost(host));
diff --git a/lib/src/fetch/response.io.dart b/lib/src/fetch/response.io.dart
index f86c9a9..7ffd1cc 100644
--- a/lib/src/fetch/response.io.dart
+++ b/lib/src/fetch/response.io.dart
@@ -22,21 +22,42 @@ final class NativeResponseHost extends ResponseHost<native.Response> {
   const NativeResponseHost(super.value);
 }
 
+final class _ResponseMetadata {
+  _ResponseMetadata({
+    required this.redirected,
+    required this.status,
+    required this.statusText,
+    required this.type,
+    required this.url,
+  });
+
+  factory _ResponseMetadata.from(
+    native.Response response, [
+    native.ResponseInit? init,
+  ]) {
+    return _ResponseMetadata(
+      redirected: response.redirected,
+      status: init?.status ?? response.status,
+      statusText: init?.statusText ?? response.statusText,
+      type: response.type,
+      url: response.url,
+    );
+  }
+
+  final bool redirected;
+  final int status;
+  final String statusText;
+  final native.ResponseType type;
+  final String url;
+}
+
 class Response implements native.Response {
   Response._(
     this._host, {
+    _ResponseMetadata? metadata,
     io_headers.Headers? headers,
-    bool? redirected,
-    int? status,
-    String? statusText,
-    native.ResponseType? type,
-    String? url,
-  }) : _headers = headers,
-       _redirected = redirected,
-       _status = status,
-       _statusText = statusText,
-       _type = type,
-       _url = url;
+  }) : _metadata = metadata,
+       _headers = headers;
 
   factory Response([Object? body, native.ResponseInit? init]) {
     return switch ((body, init)) {
@@ -70,13 +91,9 @@ class Response implements native.Response {
   }
 
   final ResponseHost _host;
+  final _ResponseMetadata? _metadata;
   io_headers.Headers? _headers;
   Body? _body;
-  final bool? _redirected;
-  final int? _status;
-  final String? _statusText;
-  final native.ResponseType? _type;
-  final String? _url;
 
   @override
   io_headers.Headers get headers {
@@ -107,8 +124,8 @@ class Response implements native.Response {
 
   @override
   bool get ok {
-    final status = _status;
-    if (status != null) return HttpStatus.isSuccess(status);
+    final metadata = _metadata;
+    if (metadata != null) return HttpStatus.isSuccess(metadata.status);
 
     return switch (_host) {
       final HttpClientResponseHost host => HttpStatus.isSuccess(
@@ -120,8 +137,8 @@ class Response implements native.Response {
 
   @override
   bool get redirected {
-    final redirected = _redirected;
-    if (redirected != null) return redirected;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.redirected;
 
     return switch (_host) {
       final HttpClientResponseHost host => host.value.redirects.isNotEmpty,
@@ -131,8 +148,8 @@ class Response implements native.Response {
 
   @override
   int get status {
-    final status = _status;
-    if (status != null) return status;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.status;
 
     return switch (_host) {
       final HttpClientResponseHost host => host.value.statusCode,
@@ -142,8 +159,8 @@ class Response implements native.Response {
 
   @override
   String get statusText {
-    final statusText = _statusText;
-    if (statusText != null) return statusText;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.statusText;
 
     return switch (_host) {
       final HttpClientResponseHost host => host.value.reasonPhrase,
@@ -153,8 +170,8 @@ class Response implements native.Response {
 
   @override
   native.ResponseType get type {
-    final type = _type;
-    if (type != null) return type;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.type;
 
     return switch (_host) {
       final HttpClientResponseHost _ => native.ResponseType.default_,
@@ -164,8 +181,8 @@ class Response implements native.Response {
 
   @override
   String get url {
-    final url = _url;
-    if (url != null) return url;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.url;
 
     return switch (_host) {
       final HttpClientResponseHost _ => '',
@@ -232,15 +249,12 @@ class Response implements native.Response {
 
   @override
   Response clone() {
+    final metadata = _ResponseMetadata.from(this);
     return switch (_host) {
       final NativeResponseHost host => Response._(
         NativeResponseHost(host.value.clone()),
+        metadata: metadata,
         headers: io_headers.Headers(headers),
-        redirected: redirected,
-        status: status,
-        statusText: statusText,
-        type: type,
-        url: url,
       ),
       final HttpClientResponseHost _ => Response._(
         NativeResponseHost(
@@ -253,9 +267,7 @@ class Response implements native.Response {
             ),
           ),
         ),
-        redirected: redirected,
-        type: type,
-        url: url,
+        metadata: metadata,
       ),
     };
   }
@@ -272,24 +284,11 @@ class Response implements native.Response {
     Response response,
     native.ResponseInit? init,
   ) {
-    if (init?.status == null && response.status == 0) {
-      final clone = response.clone();
-      return Response._(
-        clone._host,
-        headers: io_headers.Headers(init?.headers ?? response.headers),
-        redirected: response.redirected,
-        status: response.status,
-        statusText: init?.statusText ?? response.statusText,
-        type: response.type,
-        url: response.url,
-      );
-    }
-
-    return Response._(
-      NativeResponseHost(_nativeResponseFromWrappedResponse(response, init)),
-      redirected: response.redirected,
-      type: response.type,
-      url: response.url,
+    return _responseFromNativeCopySource(
+      response,
+      init,
+      cloneHost: () => response.clone()._host,
+      body: response._bodyForNativeCopy,
     );
   }
 
@@ -297,68 +296,61 @@ class Response implements native.Response {
     native.Response response,
     native.ResponseInit? init,
   ) {
-    if (init?.status == null && response.status == 0) {
-      return Response._(
-        NativeResponseHost(response.clone()),
-        headers: io_headers.Headers(init?.headers ?? response.headers),
-        redirected: response.redirected,
-        status: response.status,
-        statusText: init?.statusText ?? response.statusText,
-        type: response.type,
-        url: response.url,
-      );
-    }
-
-    return Response._(
-      NativeResponseHost(_nativeResponseFromNativeResponse(response, init)),
-      redirected: response.redirected,
-      type: response.type,
-      url: response.url,
+    return _responseFromNativeCopySource(
+      response,
+      init,
+      cloneHost: () => NativeResponseHost(response.clone()),
+      body: () => response.body,
     );
   }
 
-  static native.Response _nativeResponseFromWrappedResponse(
-    Response response,
-    native.ResponseInit? init,
-  ) {
+  static Response _responseFromNativeCopySource(
+    native.Response response,
+    native.ResponseInit? init, {
+    required ResponseHost Function() cloneHost,
+    required Body? Function() body,
+  }) {
+    final metadata = _ResponseMetadata.from(response, init);
     final sourceHeaders = io_headers.Headers(response.headers);
-    return _nativeResponseFromCopy(
-      response._bodyForNativeCopy(),
-      status: init?.status ?? response.status,
-      statusText: init?.statusText ?? response.statusText,
-      headers: init?.headers ?? sourceHeaders,
-      preserveMissingContentType:
-          init?.headers == null && !sourceHeaders.has('content-type'),
+    final effectiveHeaders = io_headers.Headers(init?.headers ?? sourceHeaders);
+    if (init?.status == null && metadata.status == 0) {
+      return Response._(
+        cloneHost(),
+        metadata: metadata,
+        headers: effectiveHeaders,
+      );
+    }
+
+    final nativeCopy = _nativeResponseFromCopy(
+      body(),
+      metadata: metadata,
+      headers: effectiveHeaders,
+      preserveMissingContentType: _shouldPreserveMissingContentType(
+        init,
+        sourceHeaders,
+      ),
     );
+    return Response._(NativeResponseHost(nativeCopy), metadata: metadata);
   }
 
-  static native.Response _nativeResponseFromNativeResponse(
-    native.Response response,
+  static bool _shouldPreserveMissingContentType(
     native.ResponseInit? init,
+    io_headers.Headers sourceHeaders,
   ) {
-    final sourceHeaders = io_headers.Headers(response.headers);
-    return _nativeResponseFromCopy(
-      response.body,
-      status: init?.status ?? response.status,
-      statusText: init?.statusText ?? response.statusText,
-      headers: init?.headers ?? sourceHeaders,
-      preserveMissingContentType:
-          init?.headers == null && !sourceHeaders.has('content-type'),
-    );
+    return init?.headers == null && !sourceHeaders.has('content-type');
   }
 
   static native.Response _nativeResponseFromCopy(
     Body? body, {
-    required int status,
-    required String statusText,
+    required _ResponseMetadata metadata,
     required Object? headers,
     required bool preserveMissingContentType,
   }) {
     final response = native.Response(
       body,
       native.ResponseInit(
-        status: status,
-        statusText: statusText,
+        status: metadata.status,
+        statusText: metadata.statusText,
         headers: headers,
       ),
     );
diff --git a/lib/src/fetch/response.js.dart b/lib/src/fetch/response.js.dart
index a593957..8ca73da 100644
--- a/lib/src/fetch/response.js.dart
+++ b/lib/src/fetch/response.js.dart
@@ -8,6 +8,7 @@ import 'package:web/web.dart' as web;
 
 import '../_internal/web_fetch_utils.dart' as web_fetch;
 import '../_internal/web_stream_bridge.dart';
+import '../core/http_status.dart';
 import 'blob.dart';
 import 'body.dart';
 import 'form_data.native.dart';
@@ -28,21 +29,55 @@ final class NativeResponseHost extends ResponseHost<native.Response> {
   const NativeResponseHost(super.value);
 }
 
+final class _ResponseMetadata {
+  _ResponseMetadata({
+    required this.redirected,
+    required this.status,
+    required this.statusText,
+    required this.type,
+    required this.url,
+  });
+
+  factory _ResponseMetadata.from(
+    native.Response response, [
+    native.ResponseInit? init,
+  ]) {
+    return _ResponseMetadata(
+      redirected: response.redirected,
+      status: init?.status ?? response.status,
+      statusText: init?.statusText ?? response.statusText,
+      type: response.type,
+      url: response.url,
+    );
+  }
+
+  factory _ResponseMetadata.fromWeb(
+    web.Response response, [
+    native.ResponseInit? init,
+  ]) {
+    return _ResponseMetadata(
+      redirected: response.redirected,
+      status: init?.status ?? response.status,
+      statusText: init?.statusText ?? response.statusText,
+      type: Response._responseTypeFromValue(response.type),
+      url: response.url,
+    );
+  }
+
+  final bool redirected;
+  final int status;
+  final String statusText;
+  final native.ResponseType type;
+  final String url;
+}
+
 class Response implements native.Response {
   Response._(
     this._host, {
+    _ResponseMetadata? metadata,
     js_headers.Headers? headers,
-    bool? redirected,
-    int? status,
-    String? statusText,
-    native.ResponseType? type,
-    String? url,
-  }) : _headers = headers,
-       _redirected = redirected,
-       _status = status,
-       _statusText = statusText,
-       _type = type,
-       _url = url;
+  }) : _metadata = metadata,
+       _headers = headers;
 
   factory Response([Object? body, native.ResponseInit? init]) {
     return switch ((body, init)) {
@@ -57,11 +92,7 @@ class Response implements native.Response {
       (final web.Response response, _) => _responseFromWebResponse(
         response,
         init,
-        redirected: response.redirected,
-        status: response.status,
-        statusText: response.statusText,
-        type: _responseTypeFromValue(response.type),
-        url: response.url,
+        _ResponseMetadata.fromWeb(response, init),
       ),
       (final native.Response response, null) => Response._(
         NativeResponseHost(response.clone()),
@@ -87,13 +118,9 @@ class Response implements native.Response {
   }
 
   final ResponseHost _host;
+  final _ResponseMetadata? _metadata;
   js_headers.Headers? _headers;
   Body? _body;
-  final bool? _redirected;
-  final int? _status;
-  final String? _statusText;
-  final native.ResponseType? _type;
-  final String? _url;
 
   @override
   js_headers.Headers get headers {
@@ -101,7 +128,9 @@ class Response implements native.Response {
     if (headers != null) return headers;
 
     return _headers = switch (_host) {
-      final WebResponseHost host => js_headers.Headers(host.value.headers),
+      final WebResponseHost host => js_headers.headersFromHost(
+        host.value.headers,
+      ),
       final NativeResponseHost host => js_headers.Headers(host.value.headers),
     };
   }
@@ -132,8 +161,8 @@ class Response implements native.Response {
 
   @override
   bool get ok {
-    final status = _status;
-    if (status != null) return status >= 200 && status <= 299;
+    final metadata = _metadata;
+    if (metadata != null) return HttpStatus.isSuccess(metadata.status);
 
     return switch (_host) {
       final WebResponseHost host => host.value.ok,
@@ -143,8 +172,8 @@ class Response implements native.Response {
 
   @override
   bool get redirected {
-    final redirected = _redirected;
-    if (redirected != null) return redirected;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.redirected;
 
     return switch (_host) {
       final WebResponseHost host => host.value.redirected,
@@ -154,8 +183,8 @@ class Response implements native.Response {
 
   @override
   int get status {
-    final status = _status;
-    if (status != null) return status;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.status;
 
     return switch (_host) {
       final WebResponseHost host => host.value.status,
@@ -165,8 +194,8 @@ class Response implements native.Response {
 
   @override
   String get statusText {
-    final statusText = _statusText;
-    if (statusText != null) return statusText;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.statusText;
 
     return switch (_host) {
       final WebResponseHost host => host.value.statusText,
@@ -176,8 +205,8 @@ class Response implements native.Response {
 
   @override
   native.ResponseType get type {
-    final type = _type;
-    if (type != null) return type;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.type;
 
     return switch (_host) {
       final WebResponseHost host => _responseTypeFromValue(host.value.type),
@@ -187,8 +216,8 @@ class Response implements native.Response {
 
   @override
   String get url {
-    final url = _url;
-    if (url != null) return url;
+    final metadata = _metadata;
+    if (metadata != null) return metadata.url;
 
     return switch (_host) {
       final WebResponseHost host => host.value.url,
@@ -276,25 +305,18 @@ class Response implements native.Response {
 
   @override
   Response clone() {
+    final metadata = _ResponseMetadata.from(this);
     return switch (_host) {
       final WebResponseHost host => _responseFromWebResponse(
         host.value,
         null,
+        metadata,
         sourceHeaders: js_headers.Headers(headers),
-        redirected: redirected,
-        status: status,
-        statusText: statusText,
-        type: type,
-        url: url,
       ),
       final NativeResponseHost host => Response._(
         NativeResponseHost(host.value.clone()),
+        metadata: metadata,
         headers: js_headers.Headers(headers),
-        redirected: redirected,
-        status: status,
-        statusText: statusText,
-        type: type,
-        url: url,
       ),
     };
   }
@@ -314,53 +336,40 @@ class Response implements native.Response {
     Response response,
     native.ResponseInit? init,
   ) {
+    final metadata = _ResponseMetadata.from(response, init);
     return switch (response._host) {
       final WebResponseHost host => _responseFromWebResponse(
         host.value,
         init,
+        metadata,
         sourceHeaders: js_headers.Headers(response.headers),
-        redirected: response.redirected,
-        status: response.status,
-        statusText: response.statusText,
-        type: response.type,
-        url: response.url,
       ),
       NativeResponseHost() => _responseFromNativeWrappedResponse(
         response,
         init,
+        metadata,
       ),
     };
   }
 
   static Response _responseFromWebResponse(
     web.Response response,
-    native.ResponseInit? init, {
+    native.ResponseInit? init,
+    _ResponseMetadata metadata, {
     Object? sourceHeaders,
-    bool? redirected,
-    int? status,
-    String? statusText,
-    native.ResponseType? type,
-    String? url,
   }) {
-    final sourceStatus = status ?? response.status;
     final effectiveHeaders = js_headers.Headers(
       init?.headers ?? sourceHeaders ?? response.headers,
     );
-    final effectiveStatusText =
-        init?.statusText ?? statusText ?? response.statusText;
-    if (init?.status == null && sourceStatus == 0) {
+    if (init?.status == null && metadata.status == 0) {
       return Response._(
         WebResponseHost(response.clone()),
+        metadata: metadata,
         headers: effectiveHeaders,
-        redirected: redirected,
-        status: sourceStatus,
-        statusText: effectiveStatusText,
-        type: type,
-        url: url,
       );
     }
 
-    final targetStatus = _validateStatus(init?.status ?? sourceStatus);
+    final targetStatus = _validateStatus(metadata.status);
     if (!_statusAllowsBody(targetStatus) && response.body != null) {
       throw ArgumentError.value(
         response,
@@ -376,43 +385,26 @@ class Response implements native.Response {
           source.body,
           web.ResponseInit(
             status: targetStatus,
-            statusText: effectiveStatusText,
+            statusText: metadata.statusText,
             headers: effectiveHeaders.host,
           ),
         ),
       ),
-      redirected: redirected,
-      status: targetStatus,
-      statusText: effectiveStatusText,
-      type: type,
-      url: url,
+      metadata: metadata,
     );
   }
 
   static Response _responseFromNativeWrappedResponse(
     Response response,
     native.ResponseInit? init,
+    _ResponseMetadata metadata,
   ) {
-    if (init?.status == null && response.status == 0) {
-      final clone = response.clone();
-      return Response._(
-        clone._host,
-        headers: js_headers.Headers(init?.headers ?? response.headers),
-        redirected: response.redirected,
-        status: response.status,
-        statusText: init?.statusText ?? response.statusText,
-        type: response.type,
-        url: response.url,
-      );
-    }
-
-    return Response._(
-      NativeResponseHost(
-        _nativeResponseFromNativeWrappedResponse(response, init),
-      ),
-      redirected: response.redirected,
-      type: response.type,
-      url: response.url,
+    return _responseFromNativeCopySource(
+      init,
+      metadata,
+      js_headers.Headers(response.headers),
+      cloneHost: () => response.clone()._host,
+      body: () => response.body,
     );
   }
 
@@ -420,24 +412,42 @@ class Response implements native.Response {
     native.Response response,
     native.ResponseInit? init,
   ) {
-    if (init?.status == null && response.status == 0) {
+    final metadata = _ResponseMetadata.from(response, init);
+    return _responseFromNativeCopySource(
+      init,
+      metadata,
+      js_headers.Headers(response.headers),
+      cloneHost: () => NativeResponseHost(response.clone()),
+      body: () => response.body,
+    );
+  }
+
+  static Response _responseFromNativeCopySource(
+    native.ResponseInit? init,
+    _ResponseMetadata metadata,
+    js_headers.Headers sourceHeaders, {
+    required ResponseHost Function() cloneHost,
+    required Body? Function() body,
+  }) {
+    final effectiveHeaders = js_headers.Headers(init?.headers ?? sourceHeaders);
+    if (init?.status == null && metadata.status == 0) {
       return Response._(
-        NativeResponseHost(response.clone()),
-        headers: js_headers.Headers(init?.headers ?? response.headers),
-        redirected: response.redirected,
-        status: response.status,
-        statusText: init?.statusText ?? response.statusText,
-        type: response.type,
-        url: response.url,
+        cloneHost(),
+        metadata: metadata,
+        headers: effectiveHeaders,
       );
     }
 
-    return Response._(
-      NativeResponseHost(_nativeResponseFromNativeResponse(response, init)),
-      redirected: response.redirected,
-      type: response.type,
-      url: response.url,
+    final nativeCopy = _nativeResponseFromCopy(
+      body(),
+      metadata: metadata,
+      headers: effectiveHeaders,
+      preserveMissingContentType: _shouldPreserveMissingContentType(
+        init,
+        sourceHeaders,
+      ),
     );
+    return Response._(NativeResponseHost(nativeCopy), metadata: metadata);
   }
 
   static int _validateStatus(int status) {
@@ -451,48 +461,24 @@ class Response implements native.Response {
     return !const <int>{204, 205, 304}.contains(status);
   }
 
-  static native.Response _nativeResponseFromNativeWrappedResponse(
-    Response response,
+  static bool _shouldPreserveMissingContentType(
     native.ResponseInit? init,
+    js_headers.Headers sourceHeaders,
   ) {
-    final sourceHeaders = js_headers.Headers(response.headers);
-    return _nativeResponseFromCopy(
-      response.body,
-      status: init?.status ?? response.status,
-      statusText: init?.statusText ?? response.statusText,
-      headers: init?.headers ?? sourceHeaders,
-      preserveMissingContentType:
-          init?.headers == null && !sourceHeaders.has('content-type'),
-    );
-  }
-
-  static native.Response _nativeResponseFromNativeResponse(
-    native.Response response,
-    native.ResponseInit? init,
-  ) {
-    final sourceHeaders = js_headers.Headers(response.headers);
-    return _nativeResponseFromCopy(
-      response.body,
-      status: init?.status ?? response.status,
-      statusText: init?.statusText ?? response.statusText,
-      headers: init?.headers ?? sourceHeaders,
-      preserveMissingContentType:
-          init?.headers == null && !sourceHeaders.has('content-type'),
-    );
+    return init?.headers == null && !sourceHeaders.has('content-type');
   }
 
   static native.Response _nativeResponseFromCopy(
     Body? body, {
-    required int status,
-    required String statusText,
+    required _ResponseMetadata metadata,
     required Object? headers,
     required bool preserveMissingContentType,
   }) {
     final response = native.Response(
       body,
       native.ResponseInit(
-        status: status,
-        statusText: statusText,
+        status: metadata.status,
+        statusText: metadata.statusText,
         headers: headers,
       ),
     );
diff --git a/test/response_io_test.dart b/test/response_io_test.dart
index c832ebc..53c832f 100644
--- a/test/response_io_test.dart
+++ b/test/response_io_test.dart
@@ -86,6 +86,7 @@ void main() {
       expect(response.statusText, 'Created');
       expect(response.headers.get('x-source'), isNull);
       expect(response.headers.get('x-init'), '1');
+      expect(response.headers.get('content-type'), 'text/plain;charset=UTF-8');
       expect(upstream.bodyUsed, isFalse);
       expect(await response.text(), 'source body');
       expect(upstream.bodyUsed, isFalse);
@@ -115,6 +116,7 @@ void main() {
       expect(response.statusText, 'Created');
       expect(response.headers.get('x-source'), isNull);
       expect(response.headers.get('x-init'), '1');
+      expect(response.headers.get('content-type'), 'text/plain;charset=UTF-8');
       expect(upstream.bodyUsed, isFalse);
       expect(await response.text(), 'native body');
       expect(upstream.bodyUsed, isFalse);
diff --git a/test/response_js_test.dart b/test/response_js_test.dart
index fc5db42..214bac1 100644
--- a/test/response_js_test.dart
+++ b/test/response_js_test.dart
@@ -122,12 +122,35 @@ void main() {
       expect(response.statusText, 'Created');
       expect(response.headers.get('x-source'), isNull);
       expect(response.headers.get('x-init'), '1');
+      expect(response.headers.get('content-type'), 'text/plain;charset=UTF-8');
       expect(upstream.bodyUsed, isFalse);
       expect(await response.text(), 'native body');
       expect(upstream.bodyUsed, isFalse);
       expect(await upstream.text(), 'native body');
     });
 
+    test(
+      'preserves body-derived content-type for native-backed wrapper copies',
+      () async {
+        final upstream = Response('wrapped body');
+
+        final response = Response(
+          upstream,
+          native.ResponseInit(headers: {'x-init': '1'}),
+        );
+
+        expect(response.headers.get('x-init'), '1');
+        expect(
+          response.headers.get('content-type'),
+          'text/plain;charset=UTF-8',
+        );
+        expect(upstream.bodyUsed, isFalse);
+        expect(await response.text(), 'wrapped body');
+        expect(upstream.bodyUsed, isFalse);
+        expect(await upstream.text(), 'wrapped body');
+      },
+    );
+
     test(
       'preserves deleted body-derived content-type when copying responses',
       () async {
@@ -254,6 +277,23 @@ void main() {
       final wrappedParsed = await wrappedCopy.formData();
       expect((wrappedParsed.get('b') as TextMultipart).value, '2');
       expect(wrapped.bodyUsed, isFalse);
+
+      final mutableCopy = Response(
+        web.Response(
+          'c=3'.toJS,
+          web.ResponseInit(
+            headers: {'content-type': 'text/plain'}.jsify()! as web.HeadersInit,
+          ),
+        ),
+        const native.ResponseInit(statusText: 'OK'),
+      );
+      mutableCopy.headers.set(
+        'content-type',
+        'application/x-www-form-urlencoded',
+      );
+
+      final mutableParsed = await mutableCopy.formData();
+      expect((mutableParsed.get('c') as TextMultipart).value, '3');
     });
 
     test('preserves zero-status web responses when copying with init', () {