diff --git a/pkg/dartdev/analysis_options.yaml b/pkg/dartdev/analysis_options.yaml
index 225c181425b..c12a7ce280d 100644
--- a/pkg/dartdev/analysis_options.yaml
+++ b/pkg/dartdev/analysis_options.yaml
@@ -4,6 +4,8 @@ analyzer:
   errors:
     # Disable implementation_imports.
     implementation_imports: ignore
+  language:
+    strict-raw-types: true
 
 linter:
   rules:
diff --git a/pkg/dartdev/lib/src/analysis_server.dart b/pkg/dartdev/lib/src/analysis_server.dart
index ac55d08bb6d..9b3c4f66613 100644
--- a/pkg/dartdev/lib/src/analysis_server.dart
+++ b/pkg/dartdev/lib/src/analysis_server.dart
@@ -290,7 +290,7 @@ class AnalysisServer {
           _streamController(event).add(params.cast<String, dynamic>());
         }
       } else if (response case {'id': final String id}) {
-        if (response case {'error': final Map error}) {
+        if (response case {'error': final Map<String, Object?> error}) {
           _requestCompleters.remove(id)?.completeError(
               RequestError.parse(error.cast<String, dynamic>()));
         } else {
diff --git a/pkg/dartdev/lib/src/core.dart b/pkg/dartdev/lib/src/core.dart
index ac08f8c3b59..1eda0d3919c 100644
--- a/pkg/dartdev/lib/src/core.dart
+++ b/pkg/dartdev/lib/src/core.dart
@@ -71,7 +71,7 @@ abstract class DartdevCommand extends Command<int> {
       ArgParser(usageLineLength: dartdevUsageLineLength);
 }
 
-extension DartDevCommand on Command {
+extension DartDevCommand<T> on Command<T> {
   /// Return whether commands should emit verbose output.
   bool get verbose => globalResults!.flag('verbose');
 
@@ -105,7 +105,7 @@ Future<int> runProcess(
   void Function(String str)? listener,
   String? cwd,
 }) async {
-  Future forward(Stream<List<int>> output, bool isStderr) {
+  Future<void> forward(Stream<List<int>> output, bool isStderr) {
     return _streamLineTransform(output, (line) {
       final trimmed = line.trimRight();
       logToTrace
@@ -129,7 +129,7 @@ Future<int> runProcess(
   return exitCode;
 }
 
-Future _streamLineTransform(
+Future<void> _streamLineTransform(
   Stream<List<int>> stream,
   Function(String line) handler,
 ) {
diff --git a/pkg/dartdev/lib/src/dds_runner.dart b/pkg/dartdev/lib/src/dds_runner.dart
index 05535f8741f..f387d3303a5 100644
--- a/pkg/dartdev/lib/src/dds_runner.dart
+++ b/pkg/dartdev/lib/src/dds_runner.dart
@@ -34,9 +34,8 @@ class DDSRunner {
     if (!isAot) {
       // On ia32 sdks we do not have an AOT runtime and so we would be
       // using the regular executable.
-      snapshotName = fullSdk
-          ? sdk.ddsSnapshot
-          : absolute(sdkDir, 'dds.dart.snapshot');
+      snapshotName =
+          fullSdk ? sdk.ddsSnapshot : absolute(sdkDir, 'dds.dart.snapshot');
       if (!Sdk.checkArtifactExists(snapshotName)) {
         return false;
       }
@@ -64,7 +63,7 @@ class DDSRunner {
     const devToolsMessagePrefix =
         'The Dart DevTools debugger and profiler is available at:';
     if (debugDds) {
-      late final StreamSubscription stdoutSub;
+      late final StreamSubscription<String> stdoutSub;
       stdoutSub = process.stdout
           .transform(utf8.decoder)
           .transform(const LineSplitter())
diff --git a/pkg/dartdev/test/analytics_test.dart b/pkg/dartdev/test/analytics_test.dart
index 3d8716b77a0..2c3247b8d12 100644
--- a/pkg/dartdev/test/analytics_test.dart
+++ b/pkg/dartdev/test/analytics_test.dart
@@ -16,11 +16,13 @@ import 'package:unified_analytics/unified_analytics.dart';
 import 'experiment_util.dart';
 import 'utils.dart';
 
-List<Map> extractAnalytics(io.ProcessResult result) {
+List<Map<String, Object?>> extractAnalytics(io.ProcessResult result) {
   return LineSplitter.split(result.stderr)
       .where((line) => line.startsWith('[analytics]: '))
-      .map((line) => json.decode(line.substring('[analytics]: '.length)) as Map)
-      .toList();
+      .map((line) {
+    return (json.decode(line.substring('[analytics]: '.length)) as Map)
+        .cast<String, Object?>();
+  }).toList();
 }
 
 void main() {
diff --git a/pkg/dartdev/test/commands/create_integration_test.dart b/pkg/dartdev/test/commands/create_integration_test.dart
index fe4262d2231..ec052b0b6fc 100644
--- a/pkg/dartdev/test/commands/create_integration_test.dart
+++ b/pkg/dartdev/test/commands/create_integration_test.dart
@@ -122,8 +122,8 @@ void defineCreateTests() {
 
         if (isLastCommand && (isServerTemplate || isWebTemplate)) {
           final completer = Completer<void>();
-          late StreamSubscription stdoutSub;
-          late StreamSubscription stderrSub;
+          late final StreamSubscription<String> stdoutSub;
+          late final StreamSubscription<String> stderrSub;
           // Listen for well-known output from specific templates to determine
           // if they've executed correctly. These templates won't exit on their
           // own, so we'll need to terminate the process once we've verified it
diff --git a/pkg/dartdev/test/commands/devtools_test.dart b/pkg/dartdev/test/commands/devtools_test.dart
index f6025e2bc59..4868d56ac0f 100644
--- a/pkg/dartdev/test/commands/devtools_test.dart
+++ b/pkg/dartdev/test/commands/devtools_test.dart
@@ -79,7 +79,7 @@ void devtools() {
       final devToolsServedCompleter = Completer<void>();
       final dtdServedCompleter = Completer<void>();
 
-      late StreamSubscription sub;
+      late final StreamSubscription<String> sub;
       sub = process!.stdout
           .transform<String>(utf8.decoder)
           .transform<String>(const LineSplitter())
@@ -157,7 +157,7 @@ void devtools() {
     bool startedDds = false;
     bool startedDtd = false;
     final devToolsServedCompleter = Completer<void>();
-    late StreamSubscription sub;
+    late final StreamSubscription<String> sub;
     sub = process.stdout
         .transform<String>(utf8.decoder)
         .transform<String>(const LineSplitter())
@@ -228,7 +228,7 @@ Future<void> main() async {
       );
 
       final serviceUriCompleter = Completer<String>();
-      late StreamSubscription sub;
+      late final StreamSubscription<String> sub;
       sub = targetProjectInstance!.stdout
           .transform(utf8.decoder)
           .transform(const LineSplitter())
diff --git a/pkg/dartdev/test/commands/flag_test.dart b/pkg/dartdev/test/commands/flag_test.dart
index 2aa42e0e6d2..42b1c871c9a 100644
--- a/pkg/dartdev/test/commands/flag_test.dart
+++ b/pkg/dartdev/test/commands/flag_test.dart
@@ -33,7 +33,7 @@ void command() {
   test('description formatting', () {
     DartdevRunner(['--suppress-analytics'])
         .commands
-        .forEach((String commandKey, Command command) {
+        .forEach((String commandKey, Command<int> command) {
       expect(commandKey, isNotEmpty);
       expect(command.description, isNotEmpty);
       expect(command.description.split('\n').first, endsWith('.'));
@@ -45,7 +45,7 @@ void command() {
   test('argParser usageLineLength', () {
     DartdevRunner(['--suppress-analytics'])
         .commands
-        .forEach((String commandKey, Command command) {
+        .forEach((String commandKey, Command<int> command) {
       if (command.name != 'help' &&
           command.name != 'format' &&
           command.name != 'pub' &&
diff --git a/pkg/dartdev/test/commands/help_test.dart b/pkg/dartdev/test/commands/help_test.dart
index 77ca650971f..429bd787c38 100644
--- a/pkg/dartdev/test/commands/help_test.dart
+++ b/pkg/dartdev/test/commands/help_test.dart
@@ -22,7 +22,7 @@ void help() {
   ];
   DartdevRunner(['--suppress-analytics'])
       .commands
-      .forEach((String commandKey, Command command) {
+      .forEach((String commandKey, Command<int> command) {
     if (!commandsNotTested.contains(commandKey)) {
       test('(help $commandKey == $commandKey --help)', () async {
         p = project();
@@ -57,7 +57,7 @@ void help() {
   test('(--help flags also have -h abbr)', () {
     DartdevRunner(['--suppress-analytics'])
         .commands
-        .forEach((String commandKey, Command command) {
+        .forEach((String commandKey, Command<int> command) {
       var helpOption = command.argParser.options['help'];
       // Some commands (like pub which use
       // "argParser = ArgParser.allowAnything()") may not have the help Option
diff --git a/pkg/dartdev/test/commands/language_server_test.dart b/pkg/dartdev/test/commands/language_server_test.dart
index 1f200109360..b9b2f7a87a7 100644
--- a/pkg/dartdev/test/commands/language_server_test.dart
+++ b/pkg/dartdev/test/commands/language_server_test.dart
@@ -27,7 +27,7 @@ void defineLanguageServerTests() {
   late utils.TestProject project;
   Process? process;
 
-  Future runWithLsp(List<String> args) async {
+  Future<void> runWithLsp(List<String> args) async {
     project = utils.project();
 
     process = await project.start(args);
diff --git a/pkg/dartdev/test/commands/run_test.dart b/pkg/dartdev/test/commands/run_test.dart
index 5aac1d53f94..4164c189577 100644
--- a/pkg/dartdev/test/commands/run_test.dart
+++ b/pkg/dartdev/test/commands/run_test.dart
@@ -531,7 +531,7 @@ void main(List<String> args) => print("$b $args");
       p.relativeFilePath,
     ]);
     final completer = Completer<void>();
-    late StreamSubscription sub;
+    late final StreamSubscription<String> sub;
     sub = process.stdout.transform(utf8.decoder).listen((event) async {
       if (event.contains(dartVMServiceRegExp)) {
         await sub.cancel();
@@ -834,7 +834,7 @@ main() => print('b:b');
         final readyCompleter = Completer<void>();
         final completer = Completer<void>();
 
-        late StreamSubscription sub;
+        late final StreamSubscription<String> sub;
         sub = process.stdout.transform(utf8.decoder).listen((event) async {
           if (event.contains('ready')) {
             readyCompleter.complete();
@@ -912,8 +912,8 @@ main() => print('b:b');
 
           final completer = Completer<void>();
 
-          late StreamSubscription sub;
-          late String uri;
+          late final StreamSubscription<String> sub;
+          late final String uri;
           sub = process.stdout.transform(utf8.decoder).listen((event) async {
             if (event.contains(dartVMServiceRegExp)) {
               uri = dartVMServiceRegExp.firstMatch(event)!.group(1)!;
diff --git a/pkg/dartdev/test/commands/test_test.dart b/pkg/dartdev/test/commands/test_test.dart
index 8794d53f23a..1b70a6f8b12 100644
--- a/pkg/dartdev/test/commands/test_test.dart
+++ b/pkg/dartdev/test/commands/test_test.dart
@@ -185,7 +185,7 @@ void main() {
         RegExp(r'(http:\/\/127.0.0.1:\d*\/[\da-zA-Z-_]*=\/)');
     final process = await p.start(['test', '--pause-after-load']);
     final completer = Completer<Uri>();
-    late StreamSubscription sub;
+    late final StreamSubscription<String> sub;
     sub = process.stdout
         .transform(utf8.decoder)
         .transform(const LineSplitter())
diff --git a/pkg/dartdev/test/smoke/smoke_test.dart b/pkg/dartdev/test/smoke/smoke_test.dart
index 48073abed10..ea7a1014889 100644
--- a/pkg/dartdev/test/smoke/smoke_test.dart
+++ b/pkg/dartdev/test/smoke/smoke_test.dart
@@ -107,7 +107,7 @@ void main() {
           ],
         );
         final completer = Completer<void>();
-        late StreamSubscription sub;
+        late final StreamSubscription<String> sub;
         bool sawServiceMsg = false;
         void onData(event) {
           print(event);
diff --git a/pkg/dartdev/tool/sdk_size.dart b/pkg/dartdev/tool/sdk_size.dart
index d6691779452..6fdcc26c0de 100644
--- a/pkg/dartdev/tool/sdk_size.dart
+++ b/pkg/dartdev/tool/sdk_size.dart
@@ -55,7 +55,8 @@ void main(List<String> arguments) {
 
 String sizeMB(int size) => '${(size / (1024.0 * 1024)).toStringAsFixed(1)}MB';
 
-Map build(FileSystemEntity entity, {Map<String, String> extra = const {}}) {
+Map<String, Object?> build(FileSystemEntity entity,
+    {Map<String, String> extra = const {}}) {
   const fsBlockSize = 4096.0;
 
   if (entity is File) {