2 files changed, 4 insertions, 4 deletions
diff --git a/error.c b/error.c
index da0355a75b..61ba07c5b4 100644
--- a/error.c
+++ b/error.c
@@ -645,8 +645,10 @@ VALUE rb_eSystemCallError;
 VALUE rb_mErrno;
 static VALUE rb_eNOERROR;
 
-static ID id_new, id_bt, id_bt_locations, id_cause, id_message, id_backtrace;
+static ID id_new, id_cause, id_message, id_backtrace;
 static ID id_status, id_name, id_args, id_Errno, id_errno, id_i_path;
+#define id_bt idBt
+#define id_bt_locations idBt_locations
 #define id_mesg idMesg
 
 #undef rb_exc_new_cstr
@@ -1908,8 +1910,6 @@ Init_Exception(void)
     rb_define_global_function("warn", rb_warn_m, -1);
 
     id_new = rb_intern_const("new");
-    id_bt = rb_intern_const("bt");
-    id_bt_locations = rb_intern_const("bt_locations");
     id_cause = rb_intern_const("cause");
     id_message = rb_intern_const("message");
     id_backtrace = rb_intern_const("backtrace");
diff --git a/vm_args.c b/vm_args.c
index 446ad482c4..9e6fb9b990 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -682,7 +682,7 @@ raise_argument_error(rb_thread_t *th, const rb_iseq_t *iseq, const VALUE exc)
 	at = rb_vm_backtrace_object();
     }
 
-    rb_iv_set(exc, "bt_locations", at);
+    rb_ivar_set(exc, idBt_locations, at);
     rb_funcall(exc, rb_intern("set_backtrace"), 1, at);
     rb_exc_raise(exc);
 }