diff --git a/example/android/local.properties b/example/android/local.properties
index 02a5a1e..5004041 100644
--- a/example/android/local.properties
+++ b/example/android/local.properties
@@ -1,4 +1,4 @@
-sdk.dir=/Users/ironman/Library/Android/sdk
-flutter.sdk=/Users/ironman/flutter
+sdk.dir=/Users/michaelgobbers/Library/Developer/Xamarin/android-sdk-macosx
+flutter.sdk=/Users/michaelgobbers/Library/Developer/flutter
 flutter.versionName=1.0.0
 flutter.versionCode=1
\ No newline at end of file
diff --git a/example/ios/Runner/GeneratedPluginRegistrant.h b/example/ios/Runner/GeneratedPluginRegistrant.h
index 3b700eb..ed9a5c6 100644
--- a/example/ios/Runner/GeneratedPluginRegistrant.h
+++ b/example/ios/Runner/GeneratedPluginRegistrant.h
@@ -7,8 +7,11 @@
 
 #import <Flutter/Flutter.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface GeneratedPluginRegistrant : NSObject
 + (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry;
 @end
 
+NS_ASSUME_NONNULL_END
 #endif /* GeneratedPluginRegistrant_h */
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 95e5eb4..f746fad 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -3,7 +3,7 @@ description: A new Flutter application.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
diff --git a/lib/image_test_utils.dart b/lib/image_test_utils.dart
index 5fa03ff..bfcd379 100644
--- a/lib/image_test_utils.dart
+++ b/lib/image_test_utils.dart
@@ -1,7 +1,7 @@
 import 'dart:async';
 import 'dart:io';
 
-import 'package:mockito/mockito.dart';
+import 'package:mocktail/mocktail.dart';
 
 /// Runs [body] in a fresh [Zone] that provides mocked responses for [Image.network] widgets.
 ///
@@ -42,7 +42,8 @@ import 'package:mockito/mockito.dart';
 ///
 /// The underlying code is taken from the Flutter repo:
 /// https://github.com/flutter/flutter/blob/master/dev/manual_tests/test/mock_image_http.dart
-R provideMockedNetworkImages<R>(R body(), {List<int> imageBytes = _transparentImage}) {
+R provideMockedNetworkImages<R>(R body(),
+    {List<int> imageBytes = _transparentImage}) {
   return HttpOverrides.runZoned(
     body,
     createHttpClient: (_) => _createMockImageHttpClient(_, imageBytes),
@@ -50,39 +51,116 @@ R provideMockedNetworkImages<R>(R body(), {List<int> imageBytes = _transparentIm
 }
 
 class MockHttpClient extends Mock implements HttpClient {}
+
 class MockHttpClientRequest extends Mock implements HttpClientRequest {}
+
 class MockHttpClientResponse extends Mock implements HttpClientResponse {}
+
 class MockHttpHeaders extends Mock implements HttpHeaders {}
 
 // Returns a mock HTTP client that responds with an image to all requests.
-MockHttpClient _createMockImageHttpClient(SecurityContext _, List<int> imageBytes) {
+MockHttpClient _createMockImageHttpClient(
+    SecurityContext? _, List<int> imageBytes) {
   final MockHttpClient client = MockHttpClient();
   final MockHttpClientRequest request = MockHttpClientRequest();
   final MockHttpClientResponse response = MockHttpClientResponse();
   final MockHttpHeaders headers = MockHttpHeaders();
 
-  when(client.getUrl(any)).thenAnswer((_) => Future<HttpClientRequest>.value(request));
-  when(request.headers).thenReturn(headers);
-  when(request.close()).thenAnswer((_) => Future<HttpClientResponse>.value(response));
-  when(response.contentLength).thenReturn(_transparentImage.length);
-  when(response.statusCode).thenReturn(HttpStatus.ok);
-  when(response.listen(any)).thenAnswer((Invocation invocation) {
-    final void Function(List<int>) onData = invocation.positionalArguments[0];
-    final void Function() onDone = invocation.namedArguments[#onDone];
-    final void Function(Object, [StackTrace]) onError = invocation.namedArguments[#onError];
-    final bool cancelOnError = invocation.namedArguments[#cancelOnError];
+  when(() => client.getUrl(any()))
+      .thenAnswer((_) => Future<HttpClientRequest>.value(request));
+  when(() => client.getUrl(any()))
+      .thenAnswer((_) => Future<HttpClientRequest>.value(request));
+  when(() => request.headers).thenReturn(headers);
+  when(() => request.close())
+      .thenAnswer((_) => Future<HttpClientResponse>.value(response));
+  when(() => response.contentLength).thenReturn(_transparentImage.length);
+  when(() => response.compressionState)
+      .thenReturn(HttpClientResponseCompressionState.notCompressed);
+  when(() => response.statusCode).thenReturn(HttpStatus.ok);
+  when(() => response.listen(any(),
+          onError: any(named: "onError"),
+          onDone: any(named: "onDone"),
+          cancelOnError: any(named: "cancelOnError")))
+      .thenAnswer((Invocation invocation) {
+    final void Function(List<int>)? onData = invocation.positionalArguments[0];
+    final void Function()? onDone = invocation.namedArguments[#onDone];
+    final void Function(Object, [StackTrace?])? onError =
+        invocation.namedArguments[#onError];
+    final bool? cancelOnError = invocation.namedArguments[#cancelOnError];
 
-    return Stream<List<int>>.fromIterable(<List<int>>[imageBytes])
-        .listen(onData, onDone: onDone, onError: onError, cancelOnError: cancelOnError);
+    return Stream<List<int>>.fromIterable(<List<int>>[imageBytes]).listen(
+        onData,
+        onDone: onDone,
+        onError: onError,
+        cancelOnError: cancelOnError);
   });
 
   return client;
 }
 
 const List<int> _transparentImage = const <int>[
-  0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49,
-  0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06,
-  0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4, 0x89, 0x00, 0x00, 0x00, 0x0A, 0x49, 0x44,
-  0x41, 0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00, 0x05, 0x00, 0x01, 0x0D,
-  0x0A, 0x2D, 0xB4, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE,
+  0x89,
+  0x50,
+  0x4E,
+  0x47,
+  0x0D,
+  0x0A,
+  0x1A,
+  0x0A,
+  0x00,
+  0x00,
+  0x00,
+  0x0D,
+  0x49,
+  0x48,
+  0x44,
+  0x52,
+  0x00,
+  0x00,
+  0x00,
+  0x01,
+  0x00,
+  0x00,
+  0x00,
+  0x01,
+  0x08,
+  0x06,
+  0x00,
+  0x00,
+  0x00,
+  0x1F,
+  0x15,
+  0xC4,
+  0x89,
+  0x00,
+  0x00,
+  0x00,
+  0x0A,
+  0x49,
+  0x44,
+  0x41,
+  0x54,
+  0x78,
+  0x9C,
+  0x63,
+  0x00,
+  0x01,
+  0x00,
+  0x00,
+  0x05,
+  0x00,
+  0x01,
+  0x0D,
+  0x0A,
+  0x2D,
+  0xB4,
+  0x00,
+  0x00,
+  0x00,
+  0x00,
+  0x49,
+  0x45,
+  0x4E,
+  0x44,
+  0xAE,
 ];
diff --git a/pubspec.yaml b/pubspec.yaml
index e291ee3..e1d4731 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -5,7 +5,7 @@ homepage: https://github.com/roughike/image_test_utils
 author: Iiro Krankka <iiro.krankka@gmail.com>
 
 environment:
-  sdk: '>=2.0.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
-  mockito: ^3.0.0
+  mocktail: ^0.1.4