1 files changed, 3 insertions, 0 deletions
diff --git a/gc.c b/gc.c
index f9048e031a..785a50d0ea 100644
--- a/gc.c
+++ b/gc.c
@@ -2332,6 +2332,9 @@ id2ref(VALUE obj, VALUE objid)
     if (!is_live_object(objspace, ptr)) {
 	rb_raise(rb_eRangeError, "%p is recycled object", p0);
     }
+    if (RBASIC(ptr)->klass == 0) {
+	rb_raise(rb_eRangeError, "%p is internal object", p0);
+    }
     return (VALUE)ptr;
 }