1 files changed, 7 insertions, 0 deletions
diff --git a/gc.c b/gc.c
index 12be1eac11..a57addf1c4 100644
--- a/gc.c
+++ b/gc.c
@@ -2400,6 +2400,13 @@ internal_object_p(VALUE obj)
 	  case T_NODE:
 	  case T_ZOMBIE:
 	    break;
+	  case T_CLASS:
+	    {
+		if (FL_TEST(obj, FL_SINGLETON)) {
+		    int rb_singleton_class_has_metaclass_p(VALUE sklass);
+		    return rb_singleton_class_has_metaclass_p(obj) == 0;
+		}
+	    }
 	  default:
 	    if (!p->as.basic.klass) break;
 	    return 0;