diff --git a/dio/lib/src/dio_mixin.dart b/dio/lib/src/dio_mixin.dart
index 97d23c641..b3bbaabbe 100644
--- a/dio/lib/src/dio_mixin.dart
+++ b/dio/lib/src/dio_mixin.dart
@@ -23,6 +23,7 @@ import 'progress_stream/io_progress_stream.dart'
 
 part 'interceptor.dart';
 
+// TODO(EVERYONE): Use `mixin class` when the lower bound of SDK is raised to 3.0.0.
 abstract class DioMixin implements Dio {
   /// The base request config for the instance.
   @override
diff --git a/dio/test/dio_mixin_test.dart b/dio/test/dio_mixin_test.dart
index 9468618bd..5d97cb5f1 100644
--- a/dio/test/dio_mixin_test.dart
+++ b/dio/test/dio_mixin_test.dart
@@ -2,6 +2,11 @@ import 'package:dio/dio.dart';
 import 'package:test/test.dart';
 
 void main() {
+  test('not thrown for implements', () {
+    expect(_TestDioMixin().interceptors, isA<Interceptors>());
+    expect(_TestDioMixinExtends().interceptors, isA<Interceptors>());
+  });
+
   test('assureResponse', () {
     final requestOptions = RequestOptions(path: '');
     final untypedResponse = Response<dynamic>(
@@ -26,3 +31,5 @@ void main() {
 }
 
 class _TestDioMixin with DioMixin implements Dio {}
+
+class _TestDioMixinExtends extends DioMixin implements Dio {}