diff --git a/dio/lib/src/dio/dio_for_native.dart b/dio/lib/src/dio/dio_for_native.dart
index 8be8d1b68..021507bc0 100644
--- a/dio/lib/src/dio/dio_for_native.dart
+++ b/dio/lib/src/dio/dio_for_native.dart
@@ -94,7 +94,7 @@ class DioForNative with DioMixin implements Dio {
     int received = 0;
 
     // Stream<Uint8List>
-    final stream = response.data!.stream;
+    final stream = response.data.stream;
     bool compressed = false;
     int total = 0;
     final contentEncoding = response.headers.value(
diff --git a/example/lib/generic.dart b/example/lib/generic.dart
index 4106a9107..444f48e15 100644
--- a/example/lib/generic.dart
+++ b/example/lib/generic.dart
@@ -42,5 +42,5 @@ void main() async {
 
   // This is the recommended way.
   final r = await dio.get<String>('https://baidu.com');
-  print(r.data?.length);
+  print(r.data.length);
 }
diff --git a/example_flutter_app/lib/main.dart b/example_flutter_app/lib/main.dart
index 43bb79349..117624921 100644
--- a/example_flutter_app/lib/main.dart
+++ b/example_flutter_app/lib/main.dart
@@ -66,7 +66,7 @@ class _MyHomePageState extends State<MyHomePage> {
                       .then((r) {
                     setState(() {
                       print(r.data);
-                      _text = r.data!.replaceAll(RegExp(r'\s'), '');
+                      _text = r.data.replaceAll(RegExp(r'\s'), '');
                     });
                   });
                 } catch (e) {
diff --git a/example_flutter_app/lib/routes/request.dart b/example_flutter_app/lib/routes/request.dart
index d44d88eae..eeb5d7a6b 100644
--- a/example_flutter_app/lib/routes/request.dart
+++ b/example_flutter_app/lib/routes/request.dart
@@ -26,7 +26,7 @@ class _RequestRouteState extends State<RequestRoute> {
               onPressed: () {
                 dio.get<String>('https://httpbin.org/get').then((r) {
                   setState(() {
-                    _text = r.data!;
+                    _text = r.data;
                   });
                 });
               },
diff --git a/plugins/cookie_manager/test/cookies_test.dart b/plugins/cookie_manager/test/cookies_test.dart
index fbadff939..eb1c44906 100644
--- a/plugins/cookie_manager/test/cookies_test.dart
+++ b/plugins/cookie_manager/test/cookies_test.dart
@@ -41,6 +41,7 @@ void main() {
     final firstRequestOptions = RequestOptions(baseUrl: exampleUrl);
 
     final mockResponse = Response(
+      data: null,
       requestOptions: firstRequestOptions,
       headers: Headers.fromMap(
         {HttpHeaders.setCookieHeader: mockFirstRequestCookies},
@@ -76,6 +77,7 @@ void main() {
       final requestOptions = RequestOptions(baseUrl: exampleUrl);
 
       final mockResponse = Response(
+        data: null,
         requestOptions: requestOptions,
         headers: Headers.fromMap(
           {HttpHeaders.setCookieHeader: mockResponseCookies},
diff --git a/plugins/http2_adapter/example/example.dart b/plugins/http2_adapter/example/example.dart
index 2e9449db2..57ea69206 100644
--- a/plugins/http2_adapter/example/example.dart
+++ b/plugins/http2_adapter/example/example.dart
@@ -14,7 +14,7 @@ void main() async {
   Response<String> response;
 
   response = await dio.get('/?xx=6');
-  print(response.data?.length);
+  print(response.data.length);
   print(response.redirects.length);
   print(response.data);
 }