diff --git a/packages/flutter_tools/lib/src/android/gradle.dart b/packages/flutter_tools/lib/src/android/gradle.dart
index 75af21b..4d2d883 100644
--- a/packages/flutter_tools/lib/src/android/gradle.dart
+++ b/packages/flutter_tools/lib/src/android/gradle.dart
@@ -122,7 +122,7 @@
   // Handle Gradle error thrown when Gradle needs to download additional
   // Android SDK components (e.g. Platform Tools), and the license
   // for that component has not been accepted.
-  final String matcher =
+  const String matcher =
     r'You have not accepted the license agreements of the following SDK components:'
     r'\s*\[(.+)\]';
   final RegExp licenseFailure = new RegExp(matcher, multiLine: true);
diff --git a/packages/flutter_tools/lib/src/base/io.dart b/packages/flutter_tools/lib/src/base/io.dart
index a2d945e..326c487 100644
--- a/packages/flutter_tools/lib/src/base/io.dart
+++ b/packages/flutter_tools/lib/src/base/io.dart
@@ -78,7 +78,7 @@
 /// Exits the process with the given [exitCode].
 typedef void ExitFunction(int exitCode);
 
-final ExitFunction _defaultExitFunction = io.exit;
+const ExitFunction _defaultExitFunction = io.exit;
 
 ExitFunction _exitFunction = _defaultExitFunction;
 
diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index e713871..29bf8c8 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -507,7 +507,7 @@
   final Map<String, String> buildSettings;
 }
 
-final String _xcodeRequirement = 'Xcode $kXcodeRequiredVersionMajor.$kXcodeRequiredVersionMinor or greater is required to develop for iOS.';
+const String _xcodeRequirement = 'Xcode $kXcodeRequiredVersionMajor.$kXcodeRequiredVersionMinor or greater is required to develop for iOS.';
 
 bool _checkXcodeVersion() {
   if (!platform.isMacOS)
diff --git a/packages/flutter_tools/lib/src/plugins.dart b/packages/flutter_tools/lib/src/plugins.dart
index 697cfdc..8a470b7 100644
--- a/packages/flutter_tools/lib/src/plugins.dart
+++ b/packages/flutter_tools/lib/src/plugins.dart
@@ -241,7 +241,7 @@
     _writeAndroidPluginRegistrant(directory, plugins);
   if (fs.isDirectorySync(fs.path.join(directory, 'ios'))) {
     _writeIOSPluginRegistrant(directory, plugins);
-    final CocoaPods cocoaPods = const CocoaPods();
+    const CocoaPods cocoaPods = const CocoaPods();
     if (plugins.isNotEmpty)
       cocoaPods.setupPodfile(directory);
     if (changed)