diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 222ed9450ab9..0f7a708c875a 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,5 +1,7 @@
-## NEXT
+## 9.0.5
 
+* Removes the unnecessary Flutter constraint.
+* Removes an unnecessary null check.
 * Aligns Dart and Flutter SDK constraints.
 
 ## 9.0.4
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 2e1992852d5f..6bebaaac49bb 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -11,7 +11,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '9.0.4';
+const String pigeonVersion = '9.0.5';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index f5a06678b395..fda8c2d2bba5 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -672,22 +672,20 @@ List<Error> _validateAst(Root root, String source) {
   final Iterable<String> customEnums = root.enums.map((Enum x) => x.name);
   for (final Class klass in root.classes) {
     for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-      if (field.type.typeArguments != null) {
-        for (final TypeDeclaration typeArgument in field.type.typeArguments) {
-          if (!typeArgument.isNullable) {
-            result.add(Error(
-              message:
-                  'Generic type arguments must be nullable in field "${field.name}" in class "${klass.name}".',
-              lineNumber: _calculateLineNumberNullable(source, field.offset),
-            ));
-          }
-          if (customEnums.contains(typeArgument.baseName)) {
-            result.add(Error(
-              message:
-                  'Enum types aren\'t supported in type arguments in "${field.name}" in class "${klass.name}".',
-              lineNumber: _calculateLineNumberNullable(source, field.offset),
-            ));
-          }
+      for (final TypeDeclaration typeArgument in field.type.typeArguments) {
+        if (!typeArgument.isNullable) {
+          result.add(Error(
+            message:
+                'Generic type arguments must be nullable in field "${field.name}" in class "${klass.name}".',
+            lineNumber: _calculateLineNumberNullable(source, field.offset),
+          ));
+        }
+        if (customEnums.contains(typeArgument.baseName)) {
+          result.add(Error(
+            message:
+                'Enum types aren\'t supported in type arguments in "${field.name}" in class "${klass.name}".',
+            lineNumber: _calculateLineNumberNullable(source, field.offset),
+          ));
         }
       }
       if (!(validTypes.contains(field.type.baseName) ||
diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index b5c399691179..d6289b4d56fc 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index c926e8b00561..71d22916a982 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import
 // ignore_for_file: avoid_relative_lib_imports
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
index 175400a35e1a..5258c81cbe4b 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.alternate_language_test_plugin;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index 2886734d1470..32e8ed7c8aa5 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #import <Foundation/Foundation.h>
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
index 90e3872cf85a..3402a274e630 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #import "CoreTests.gen.h"
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
index 585bd5566849..ac5c741d4191 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/flutter_unittests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/flutter_unittests.gen.dart
index 352863832871..e5187c3193c1 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/flutter_unittests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/flutter_unittests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
index 431d5205d287..86ae58b88d0c 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
index 625d29d750fc..de3f06dbfe36 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
index 5247846624c9..011c969194da 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
index 89b7b8c40286..5b9b1d7a1583 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.gen.dart
index 873e4e62cd8d..7bf628c364c6 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index 585bd5566849..ac5c741d4191 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index 8b0d4c05d7ab..1884bd2b5cd7 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.test_plugin
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index 6b087b7faaa6..a5fca2869c1d 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index 6b087b7faaa6..a5fca2869c1d 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
index 5bd1b8867a83..fb7ec879e25e 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #undef _HAS_EXCEPTIONS
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index 59a7d977c783..83c28aa13ff6 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v9.0.4), do not edit directly.
+// Autogenerated from Pigeon (v9.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #ifndef PIGEON_CORE_TESTS_GEN_H_
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index b3df00f62118..c686386888fa 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,11 +2,10 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 9.0.4 # This must match the version in lib/generator_tools.dart
+version: 9.0.5 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.17.0 <3.0.0"
-  flutter: ">=3.0.0"
 
 dependencies:
   analyzer: "^5.2.0"