1 files changed, 1 insertions, 1 deletions
diff --git a/class.c b/class.c
index 0f4394d97d..f8407ca77b 100644
--- a/class.c
+++ b/class.c
@@ -1258,7 +1258,7 @@ rb_define_attr(VALUE klass, const char *name, int read, int write)
 }
 
 int
-rb_obj_basic_to_s_p(obj)
+rb_obj_basic_to_s_p(VALUE obj)
 {
     const rb_method_entry_t *me = rb_method_entry(CLASS_OF(obj), rb_intern("to_s"));
     if (me && me->def && me->def->type == VM_METHOD_TYPE_CFUNC &&