Index: src/Virtual/ExpandCasts.cc
===================================================================
--- src/Virtual/ExpandCasts.cc	(revision 3606fe4fcb57ddc626e19a892c71e8e351bda641)
+++ src/Virtual/ExpandCasts.cc	(revision 09f34a84d91d0f6c3dcd80079886a3a4dd8e7ec7)
@@ -317,5 +317,5 @@
 };
 
-struct ExpandCastsCore {
+struct ExpandCastsCore final {
 	void previsit( ast::FunctionDecl const * decl );
 	void previsit( ast::StructDecl const * decl );