diff --git a/LanguageFeatures/Extension-types/static_analysis_extension_types_A10_t14.dart b/LanguageFeatures/Extension-types/static_analysis_extension_types_A10_t14.dart
new file mode 100644
index 0000000000..078710127b
--- /dev/null
+++ b/LanguageFeatures/Extension-types/static_analysis_extension_types_A10_t14.dart
@@ -0,0 +1,63 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A compile-time error occurs if an extension type has a
+/// non-extension superinterface whose transitive alias expansion is a type
+/// variable, a deferred type, any top type (including dynamic and void), the
+/// type Null, any function type, the type Function, any record type, the type
+/// Record, or any type of the form T? or FutureOr<T> for any type T.
+///
+/// @description Checks that it is not an error if an representation type of an
+/// extension type is a  top type, the type `Null`, a function type, the type
+/// `Function`, a record type, the type `Record`, a type of the form `T?` or
+/// `FutureOr<T>`
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "dart:async" show FutureOr;
+import "../../Utils/expect.dart";
+import "../../Utils/static_type_helper.dart";
+
+typedef void Foo();
+
+extension type ET1(dynamic id) {}
+
+extension type ET2(Object id) {}
+
+extension type ET3(Object? id) {}
+
+extension type ET4(Null id) {}
+
+extension type ET5(Never id) {}
+
+extension type ET6(Foo id) {}
+
+extension type ET7(Function id) {}
+
+extension type ET8((int,) id) {}
+
+extension type ET9(Record id) {}
+
+extension type ET10(int? id) {}
+
+extension type ET11(FutureOr<int> id) {}
+
+Never never() => throw Exception();
+
+Foo foo = () {};
+
+main() {
+  Expect.throws(() {ET1("42").id.whatever;});
+  ET2(42).id.expectStaticType<Exactly<Object>>();
+  ET3(42).id.expectStaticType<Exactly<Object?>>();
+  ET4(null).id.expectStaticType<Exactly<Null>>();
+  Expect.throws(() {ET5(never());});
+  ET6(foo).id.expectStaticType<Exactly<Foo>>();
+  ET7(() {}).id.expectStaticType<Exactly<Function>>();
+  ET8((42,)).id.expectStaticType<Exactly<(int,)>>();
+  ET9((42,)).id.expectStaticType<Exactly<Record>>();
+  ET10(null).id.expectStaticType<Exactly<int?>>();
+  ET11(42).id.expectStaticType<Exactly<FutureOr<int>>>();
+}
diff --git a/LanguageFeatures/Extension-types/static_analysis_extension_types_A10_t15.dart b/LanguageFeatures/Extension-types/static_analysis_extension_types_A10_t15.dart
new file mode 100644
index 0000000000..3434d309e9
--- /dev/null
+++ b/LanguageFeatures/Extension-types/static_analysis_extension_types_A10_t15.dart
@@ -0,0 +1,24 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A compile-time error occurs if an extension type has a
+/// non-extension superinterface whose transitive alias expansion is a type
+/// variable, a deferred type, any top type (including dynamic and void), the
+/// type Null, any function type, the type Function, any record type, the type
+/// Record, or any type of the form T? or FutureOr<T> for any type T.
+///
+/// @description Checks that it is not an error if an representation type of an
+/// extension type is a type `void`
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+extension type ET1(void id) {}
+
+main() {
+  print(ET1("42").id);
+//                ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}