diff --git a/LanguageFeatures/Patterns/switch_expression_A03_t12.dart b/LanguageFeatures/Patterns/switch_expression_A03_t12.dart
index cbd43340b7..5f8766126f 100644
--- a/LanguageFeatures/Patterns/switch_expression_A03_t12.dart
+++ b/LanguageFeatures/Patterns/switch_expression_A03_t12.dart
@@ -39,7 +39,7 @@ import "../../Utils/expect.dart";
 
 String log = "";
 
-class A {
+abstract class A {
   void foo();
   void bar();
 }