diff --git a/src/ast_handlers.hpp b/src/ast_handlers.hpp
index 580ea86..b19ece0 100644
--- a/src/ast_handlers.hpp
+++ b/src/ast_handlers.hpp
@@ -214,6 +214,7 @@
     }
 };
 
+struct discard_class;
 
 struct ls_class;