1 files changed, 1 insertions, 0 deletions
diff --git a/node.h b/node.h
index a1f01ed088..3741e649ca 100644
--- a/node.h
+++ b/node.h
@@ -406,6 +406,7 @@ rb_ast_t *rb_ast_new(void);
 void rb_ast_mark(rb_ast_t*);
 void rb_ast_dispose(rb_ast_t*);
 void rb_ast_free(rb_ast_t*);
+size_t rb_ast_memsize(const rb_ast_t*);
 void rb_ast_add_mark_object(rb_ast_t*, VALUE);
 NODE *rb_ast_newnode(rb_ast_t*);
 void rb_ast_delete_node(rb_ast_t*, NODE *n);