diff --git a/dev/bots/pubspec.yaml b/dev/bots/pubspec.yaml
index 83a544245a..752f040041 100644
--- a/dev/bots/pubspec.yaml
+++ b/dev/bots/pubspec.yaml
@@ -21,7 +21,7 @@ dependencies:
 
 dev_dependencies:
   test: 0.12.33
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
 
   barback: 0.15.2+15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -59,4 +59,4 @@ dev_dependencies:
   web_socket_channel: 1.0.7 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.13 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: 73c1
+# PUBSPEC CHECKSUM: e7c2
diff --git a/dev/manual_tests/pubspec.yaml b/dev/manual_tests/pubspec.yaml
index 6b0d977fad..22ca1c941b 100644
--- a/dev/manual_tests/pubspec.yaml
+++ b/dev/manual_tests/pubspec.yaml
@@ -13,7 +13,7 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
 
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
 
   args: 1.4.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   async: 2.0.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -64,4 +64,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 2bbb
+# PUBSPEC CHECKSUM: a9bc
diff --git a/dev/tools/pubspec.yaml b/dev/tools/pubspec.yaml
index 6ddd90f77e..c642181765 100644
--- a/dev/tools/pubspec.yaml
+++ b/dev/tools/pubspec.yaml
@@ -24,7 +24,7 @@ dependencies:
 
 dev_dependencies:
   test: 0.12.33
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
 
   barback: 0.15.2+15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -60,4 +60,4 @@ dev_dependencies:
   web_socket_channel: 1.0.7 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.13 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: c7ca
+# PUBSPEC CHECKSUM: 3ccb
diff --git a/packages/flutter/pubspec.yaml b/packages/flutter/pubspec.yaml
index 32c5504daf..9712208b95 100644
--- a/packages/flutter/pubspec.yaml
+++ b/packages/flutter/pubspec.yaml
@@ -16,7 +16,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
 
   args: 1.4.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   async: 2.0.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -67,4 +67,4 @@ dev_dependencies:
 environment:
   sdk: '>=1.19.0 <2.0.0'
 
-# PUBSPEC CHECKSUM: 2bbb
+# PUBSPEC CHECKSUM: a9bc
diff --git a/packages/flutter_driver/pubspec.yaml b/packages/flutter_driver/pubspec.yaml
index 87cb1c3ddb..f52df0dbb0 100644
--- a/packages/flutter_driver/pubspec.yaml
+++ b/packages/flutter_driver/pubspec.yaml
@@ -66,7 +66,7 @@ dependencies:
 
 dev_dependencies:
   test: 0.12.33
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
   quiver: 0.29.0+1
 
-# PUBSPEC CHECKSUM: 8a7e
+# PUBSPEC CHECKSUM: 397f
diff --git a/packages/flutter_localizations/pubspec.yaml b/packages/flutter_localizations/pubspec.yaml
index 2d3590631f..c115817762 100644
--- a/packages/flutter_localizations/pubspec.yaml
+++ b/packages/flutter_localizations/pubspec.yaml
@@ -15,7 +15,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
 
   args: 1.4.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   async: 2.0.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -62,4 +62,4 @@ dev_dependencies:
   web_socket_channel: 1.0.7 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.13 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: 809b
+# PUBSPEC CHECKSUM: fe9c
diff --git a/packages/flutter_tools/lib/src/commands/update_packages.dart b/packages/flutter_tools/lib/src/commands/update_packages.dart
index dad111924d..9d377a2b5e 100644
--- a/packages/flutter_tools/lib/src/commands/update_packages.dart
+++ b/packages/flutter_tools/lib/src/commands/update_packages.dart
@@ -27,7 +27,7 @@ import '../runner/flutter_command.dart';
 /// ```
 const Map<String, String> _kManuallyPinnedDependencies = const <String, String>{
   // Add pinned packages here.
-  'mockito': '3.0.0-alpha+2', // TODO(aam): https://github.com/dart-lang/mockito/issues/110
+  'mockito': '3.0.0-alpha+3', // TODO(aam): https://github.com/dart-lang/mockito/issues/110
 };
 
 class UpdatePackagesCommand extends FlutterCommand {
@@ -1202,4 +1202,4 @@ const List<String> _ignoreForChecksum = const <String>[
   'front_end',
   'kernel',
   'sky_engine',
-];
\ No newline at end of file
+];
diff --git a/packages/flutter_tools/pubspec.yaml b/packages/flutter_tools/pubspec.yaml
index a3b1dc6250..b6609f879a 100644
--- a/packages/flutter_tools/pubspec.yaml
+++ b/packages/flutter_tools/pubspec.yaml
@@ -81,7 +81,7 @@ dependencies:
 
 dev_dependencies:
   collection: 1.14.6
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
 
 dartdoc:
   # Exclude this package from the hosted API docs.
@@ -95,4 +95,4 @@ dependency_overrides:
   kernel:
     path: ../../bin/cache/dart-sdk/lib/kernel
 
-# PUBSPEC CHECKSUM: 7834
+# PUBSPEC CHECKSUM: 9735
diff --git a/packages/flutter_tools/test/analytics_test.dart b/packages/flutter_tools/test/analytics_test.dart
index f9fb7b25cd..6b9872aa17 100644
--- a/packages/flutter_tools/test/analytics_test.dart
+++ b/packages/flutter_tools/test/analytics_test.dart
@@ -96,7 +96,7 @@ void main() {
 
     testUsingContext('flutter commands send timing events', () async {
       mockTimes = <int>[1000, 2000];
-      when(mockDoctor.diagnose(androidLicenses: false, verbose: false)).thenReturn(true);
+      when(mockDoctor.diagnose(androidLicenses: false, verbose: false)).thenAnswer((_) async => true);
       final DoctorCommand command = new DoctorCommand();
       final CommandRunner<Null> runner = createTestCommandRunner(command);
       await runner.run(<String>['doctor']);
@@ -115,7 +115,7 @@ void main() {
 
     testUsingContext('doctor fail sends warning', () async {
       mockTimes = <int>[1000, 2000];
-      when(mockDoctor.diagnose(androidLicenses: false, verbose: false)).thenReturn(false);
+      when(mockDoctor.diagnose(androidLicenses: false, verbose: false)).thenAnswer((_) async => false);
       final DoctorCommand command = new DoctorCommand();
       final CommandRunner<Null> runner = createTestCommandRunner(command);
       await runner.run(<String>['doctor']);
diff --git a/packages/flutter_tools/test/base/context_test.dart b/packages/flutter_tools/test/base/context_test.dart
index a58abf7d50..ba7f8c21a2 100644
--- a/packages/flutter_tools/test/base/context_test.dart
+++ b/packages/flutter_tools/test/base/context_test.dart
@@ -174,7 +174,7 @@ void main() {
       test('returns the value returned by body', () async {
         expect(await context.run<int>(body: () => 123), 123);
         expect(await context.run<String>(body: () => 'value'), 'value');
-        expect(await context.run<Future<int>>(body: () async => 456), 456);
+        expect(await context.run<int>(body: () async => 456), 456);
       });
 
       test('passes name to child context', () async {
diff --git a/packages/flutter_tools/test/commands/install_test.dart b/packages/flutter_tools/test/commands/install_test.dart
index 0ab0cc673e..2a71342ab2 100644
--- a/packages/flutter_tools/test/commands/install_test.dart
+++ b/packages/flutter_tools/test/commands/install_test.dart
@@ -17,8 +17,8 @@ void main() {
       applyMocksToCommand(command);
 
       final MockAndroidDevice device = new MockAndroidDevice();
-      when(device.isAppInstalled(any)).thenReturn(false);
-      when(device.installApp(any)).thenReturn(true);
+      when(device.isAppInstalled(any)).thenAnswer((_) async => false);
+      when(device.installApp(any)).thenAnswer((_) async => true);
       testDeviceManager.addDevice(device);
 
       await createTestCommandRunner(command).run(<String>['install']);
@@ -29,8 +29,8 @@ void main() {
       applyMocksToCommand(command);
 
       final MockIOSDevice device = new MockIOSDevice();
-      when(device.isAppInstalled(any)).thenReturn(false);
-      when(device.installApp(any)).thenReturn(true);
+      when(device.isAppInstalled(any)).thenAnswer((_) async => false);
+      when(device.installApp(any)).thenAnswer((_) async => true);
       testDeviceManager.addDevice(device);
 
       await createTestCommandRunner(command).run(<String>['install']);
diff --git a/packages/flutter_tools/test/compile_test.dart b/packages/flutter_tools/test/compile_test.dart
index c36edd8bb9..f50578993c 100644
--- a/packages/flutter_tools/test/compile_test.dart
+++ b/packages/flutter_tools/test/compile_test.dart
@@ -35,7 +35,7 @@ void main() {
       when(mockProcessManager.canRun(any)).thenReturn(true);
       when(mockProcessManager.start(any)).thenAnswer(
           (Invocation invocation) => new Future<Process>.value(mockFrontendServer));
-      when(mockFrontendServer.exitCode).thenReturn(0);
+      when(mockFrontendServer.exitCode).thenAnswer((_) async => 0);
     });
 
     testUsingContext('single dart successful compilation', () async {
@@ -77,7 +77,7 @@ void main() {
     });
 
     testUsingContext('single dart abnormal compiler termination', () async {
-      when(mockFrontendServer.exitCode).thenReturn(255);
+      when(mockFrontendServer.exitCode).thenAnswer((_) async => 255);
 
       final BufferLogger logger = context[Logger];
 
diff --git a/packages/flutter_tools/test/ios/code_signing_test.dart b/packages/flutter_tools/test/ios/code_signing_test.dart
index fcd552216b..fe38a0cd2b 100644
--- a/packages/flutter_tools/test/ios/code_signing_test.dart
+++ b/packages/flutter_tools/test/ios/code_signing_test.dart
@@ -130,7 +130,7 @@ void main() {
             ))
           ));
       when(mockProcess.stderr).thenAnswer((Invocation invocation) => mockStdErr);
-      when(mockProcess.exitCode).thenReturn(0);
+      when(mockProcess.exitCode).thenAnswer((_) async => 0);
 
       final Map<String, String> signingConfigs = await getCodeSigningIdentityDevelopmentTeam(iosApp: app);
 
@@ -185,7 +185,7 @@ void main() {
             ))
           ));
       when(mockProcess.stderr).thenAnswer((Invocation invocation) => mockStdErr);
-      when(mockProcess.exitCode).thenReturn(0);
+      when(mockProcess.exitCode).thenAnswer((_) async => 0);
 
       final Map<String, String> signingConfigs = await getCodeSigningIdentityDevelopmentTeam(iosApp: app);
 
diff --git a/packages/flutter_tools/test/ios/ios_workflow_test.dart b/packages/flutter_tools/test/ios/ios_workflow_test.dart
index 395c7da290..6ee3c24483 100644
--- a/packages/flutter_tools/test/ios/ios_workflow_test.dart
+++ b/packages/flutter_tools/test/ios/ios_workflow_test.dart
@@ -253,9 +253,9 @@ void main() {
           .thenReturn('Xcode 8.2.1\nBuild version 8C1002\n');
       when(xcode.isInstalledAndMeetsVersionCheck).thenReturn(true);
       when(xcode.eulaSigned).thenReturn(true);
-      when(cocoaPods.isCocoaPodsInstalledAndMeetsVersionCheck).thenReturn(false);
-      when(cocoaPods.hasCocoaPods).thenReturn(true);
-      when(cocoaPods.isCocoaPodsInitialized).thenReturn(false);
+      when(cocoaPods.isCocoaPodsInstalledAndMeetsVersionCheck).thenAnswer((_) async => false);
+      when(cocoaPods.hasCocoaPods).thenAnswer((_) async => true);
+      when(cocoaPods.isCocoaPodsInitialized).thenAnswer((_) async => false);
       when(xcode.isSimctlInstalled).thenReturn(true);
 
       final ValidationResult result = await new IOSWorkflowTestTarget().validate();
diff --git a/packages/flutter_tools/test/ios/simulators_test.dart b/packages/flutter_tools/test/ios/simulators_test.dart
index dd2b599caa..b6ee8ee052 100644
--- a/packages/flutter_tools/test/ios/simulators_test.dart
+++ b/packages/flutter_tools/test/ios/simulators_test.dart
@@ -306,8 +306,7 @@ void main() {
         when(mockProcess.exitCode)
             .thenAnswer((Invocation invocation) => new Future<int>.delayed(Duration.zero, () => 0));
         return new Future<Process>.value(mockProcess);
-      })
-          .thenThrow(new TestFailure('Should start one process only'));
+      });
 
       final IOSSimulator device = new IOSSimulator('123456', category: 'iOS 11.0');
       final DeviceLogReader logReader = device.getLogReader(
diff --git a/packages/flutter_tools/test/version_test.dart b/packages/flutter_tools/test/version_test.dart
index 8495328214..e3f1ed8739 100644
--- a/packages/flutter_tools/test/version_test.dart
+++ b/packages/flutter_tools/test/version_test.dart
@@ -396,7 +396,7 @@ void fakeData(
     throw new StateError('Unexpected call to Cache.setStampFor(${invocation.positionalArguments}, ${invocation.namedArguments})');
   });
 
-  final Answering syncAnswer = (Invocation invocation) {
+  final Answering<ProcessResult> syncAnswer = (Invocation invocation) {
     bool argsAre(String a1, [String a2, String a3, String a4, String a5, String a6, String a7, String a8]) {
       const ListEquality<String> equality = const ListEquality<String>();
       final List<String> args = invocation.positionalArguments.single;
diff --git a/packages/fuchsia_remote_debug_protocol/pubspec.yaml b/packages/fuchsia_remote_debug_protocol/pubspec.yaml
index 5eba2bff96..b0ed3d96ae 100644
--- a/packages/fuchsia_remote_debug_protocol/pubspec.yaml
+++ b/packages/fuchsia_remote_debug_protocol/pubspec.yaml
@@ -62,7 +62,7 @@ dependencies:
   yaml: 2.1.13 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
 dev_dependencies:
-  mockito: 3.0.0-alpha+2
+  mockito: 3.0.0-alpha+3
   test: 0.12.33
 
-# PUBSPEC CHECKSUM: 763
+# PUBSPEC CHECKSUM: b764