Fixed `mrb_iv_remove` with immediate objects; fix #4519

The #4520 tried to address the issue, but it changes the type of
`mrb_check_frozen` argument; close #4520

1 files changed, 1 insertions, 1 deletions

diff --git a/src/variable.c b/src/variable.c
index 23d900b7d..e6f2f397e 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -521,11 +521,11 @@ mrb_obj_iv_inspect(mrb_state *mrb, struct RObject *obj)
 MRB_API mrb_value
 mrb_iv_remove(mrb_state *mrb, mrb_value obj, mrb_sym sym)
 {
-  mrb_check_frozen(mrb, mrb_obj_ptr(obj));
   if (obj_iv_p(obj)) {
     iv_tbl *t = mrb_obj_ptr(obj)->iv;
     mrb_value val;
 
+    mrb_check_frozen(mrb, mrb_obj_ptr(obj));
     if (iv_del(mrb, t, sym, &val)) {
       return val;
     }