diff --git a/pkg/analysis_server/lib/src/services/correction/dart/add_return_type.dart b/pkg/analysis_server/lib/src/services/correction/dart/add_return_type.dart
index 7c2575178be..36768a32a55 100644
--- a/pkg/analysis_server/lib/src/services/correction/dart/add_return_type.dart
+++ b/pkg/analysis_server/lib/src/services/correction/dart/add_return_type.dart
@@ -18,8 +18,7 @@ class AddReturnType extends ResolvedCorrectionProducer {
   AddReturnType({required super.context});
 
   @override
-  CorrectionApplicability get applicability =>
-      CorrectionApplicability.automatically;
+  CorrectionApplicability get applicability => .automatically;
 
   @override
   AssistKind get assistKind => DartAssistKind.addReturnType;
@@ -98,18 +97,18 @@ class AddReturnType extends ResolvedCorrectionProducer {
       if (body.isGenerator) {
         return typeProvider.streamElement.instantiate(
           typeArguments: [baseType],
-          nullabilitySuffix: baseType.nullabilitySuffix,
+          nullabilitySuffix: .none,
         );
       } else {
         return typeProvider.futureElement.instantiate(
           typeArguments: [baseType],
-          nullabilitySuffix: baseType.nullabilitySuffix,
+          nullabilitySuffix: .none,
         );
       }
     } else if (body.isGenerator) {
       return typeProvider.iterableElement.instantiate(
         typeArguments: [baseType],
-        nullabilitySuffix: baseType.nullabilitySuffix,
+        nullabilitySuffix: .none,
       );
     }
     return baseType;
diff --git a/pkg/analysis_server/test/src/services/correction/assist/add_return_type_test.dart b/pkg/analysis_server/test/src/services/correction/assist/add_return_type_test.dart
index 836ad01190b..0c42a7901df 100644
--- a/pkg/analysis_server/test/src/services/correction/assist/add_return_type_test.dart
+++ b/pkg/analysis_server/test/src/services/correction/assist/add_return_type_test.dart
@@ -184,6 +184,45 @@ String f() {
 ''');
   }
 
+  Future<void> test_topLevelFunction_block_async() async {
+    await resolveTestCode('''
+^f(String? s) async {
+  return s;
+}
+''');
+    await assertHasAssist('''
+Future<String?> f(String? s) async {
+  return s;
+}
+''');
+  }
+
+  Future<void> test_topLevelFunction_block_asyncStar() async {
+    await resolveTestCode('''
+^f(String? s) async* {
+  yield s;
+}
+''');
+    await assertHasAssist('''
+Stream<String?> f(String? s) async* {
+  yield s;
+}
+''');
+  }
+
+  Future<void> test_topLevelFunction_block_syncStar() async {
+    await resolveTestCode('''
+^f(String? s) sync* {
+  yield s;
+}
+''');
+    await assertHasAssist('''
+Iterable<String?> f(String? s) sync* {
+  yield s;
+}
+''');
+  }
+
   Future<void> test_topLevelFunction_expression() async {
     await resolveTestCode('''
 ^f() => '';