1 files changed, 1 insertions, 0 deletions
diff --git a/class.c b/class.c
index f92ceda8e4..d26269d2c8 100644
--- a/class.c
+++ b/class.c
@@ -540,6 +540,7 @@ rb_singleton_class(obj)
     else {
 	FL_UNSET(klass, FL_TAINT);
     }
+    if (OBJ_FROZEN(obj)) OBJ_FREEZE(klass);
 
     return klass;
 }