diff --git a/gc.c b/gc.c
index 5f6c751efc..9bf741025e 100644
--- a/gc.c
+++ b/gc.c
@@ -8697,12 +8697,6 @@ rb_copy_wb_protected_attribute(VALUE dest, VALUE obj)
     }
 }
 
-VALUE
-rb_obj_rgengc_promoted_p(VALUE obj)
-{
-    return RBOOL(OBJ_PROMOTED(obj));
-}
-
 size_t
 rb_obj_gc_flags(VALUE obj, ID* flags, size_t max)
 {