Index: src/Virtual/ExpandCasts.cc
===================================================================
--- src/Virtual/ExpandCasts.cc	(revision 3606fe4fcb57ddc626e19a892c71e8e351bda641)
+++ src/Virtual/ExpandCasts.cc	(revision a2fd937999535f46b6546d640ca7d676c1362c18)
@@ -317,5 +317,5 @@
 };
 
-struct ExpandCastsCore {
+struct ExpandCastsCore final {
 	void previsit( ast::FunctionDecl const * decl );
 	void previsit( ast::StructDecl const * decl );