diff --git a/include/igloo/ro.h b/include/igloo/ro.h
index 86560cf..ef4bb7c 100644
--- a/include/igloo/ro.h
+++ b/include/igloo/ro.h
@@ -84,6 +84,7 @@ struct igloo_ro_base_tag {
 	/* Associated objects */
     igloo_ro_t associated;
 };
+int igloo_ro_new__return_zero(igloo_ro_t self, const igloo_ro_type_t *type, va_list ap);
 /* ---[ END PRIVATE ]--- */
 
 #ifdef igloo_HAVE_TYPE_ATTRIBUTE_TRANSPARENT_UNION