diff --git a/dio/lib/src/adapter.dart b/dio/lib/src/adapter.dart
index 5b8ebd3e5..7d3b589a3 100644
--- a/dio/lib/src/adapter.dart
+++ b/dio/lib/src/adapter.dart
@@ -75,7 +75,9 @@ class ResponseBody {
     this.statusMessage,
     this.isRedirect = false,
     Map<String, List<String>>? headers,
-  })  : stream = Stream.value(Uint8List.fromList(bytes)),
+  })  : stream = Stream.value(
+          bytes is Uint8List ? bytes : Uint8List.fromList(bytes),
+        ),
         headers = headers ?? {};
 
   /// Whether this response is a redirect.
diff --git a/dio/lib/src/adapters/io_adapter.dart b/dio/lib/src/adapters/io_adapter.dart
index e89a927d0..e0683300e 100644
--- a/dio/lib/src/adapters/io_adapter.dart
+++ b/dio/lib/src/adapters/io_adapter.dart
@@ -200,7 +200,10 @@ class IOHttpClientAdapter implements HttpClientAdapter {
     }
 
     int dataLength = 0;
-    final stream = responseStream.transform<Uint8List>(
+
+    /// Casting the stream to Uint8List is safe due to [_HttpClientResponse]
+    /// working on a Uint8List.
+    final stream = responseStream.cast<Uint8List>().transform<Uint8List>(
       StreamTransformer.fromHandlers(
         handleData: (data, sink) {
           if (cancellation != null) {
@@ -226,7 +229,7 @@ class IOHttpClientAdapter implements HttpClientAdapter {
             dataLength += data.length,
             responseStream.contentLength,
           );
-          sink.add(Uint8List.fromList(data));
+          sink.add(data);
         },
       ),
     );