-// cs0108.cs: The new keyword is required on 'Derived.Prop(int)' because it hides inherited member
-// Line: 13
+// CS0108: `Derived.Prop' hides inherited member `Base.Prop(int)'. Use the new keyword if hiding was intended
+// Line: 10
+// Compiler options: -warnaserror -warn:2
class Base {
public void Prop (int a) {}