2 files changed, 3 insertions, 1 deletions
diff --git a/src/string.c b/src/string.c
index ed58c484b..856e908af 100644
--- a/src/string.c
+++ b/src/string.c
@@ -973,6 +973,8 @@ mrb_str_to_str(mrb_state *mrb, mrb_value str)
   switch (mrb_type(str)) {
   case MRB_TT_STRING:
     return str;
+  case MRB_TT_SYMBOL:
+    return mrb_sym2str(mrb, mrb_symbol(str));
   case MRB_TT_FIXNUM:
     return mrb_fixnum_to_str(mrb, str, 10);
   case MRB_TT_CLASS:
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;
     }