1 files changed, 6 insertions, 6 deletions
diff --git a/error.c b/error.c
index f12c89041a..77d63d7b38 100644
--- a/error.c
+++ b/error.c
@@ -495,14 +495,14 @@ exc_inspect(VALUE exc)
 static VALUE
 exc_backtrace(VALUE exc)
 {
-    ID bt = rb_intern("bt");
+    static ID bt;
 
-    if (!rb_ivar_defined(exc, bt)) return Qnil;
-    return rb_ivar_get(exc, bt);
+    if (!bt) bt = rb_intern("bt");
+    return rb_attr_get(exc, bt);
 }
 
-static VALUE
-check_backtrace(VALUE bt)
+VALUE
+rb_check_backtrace(VALUE bt)
 {
     long i;
     static const char *err = "backtrace must be Array of String";
@@ -536,7 +536,7 @@ check_backtrace(VALUE bt)
 static VALUE
 exc_set_backtrace(VALUE exc, VALUE bt)
 {
-    return rb_iv_set(exc, "bt", check_backtrace(bt));
+    return rb_iv_set(exc, "bt", rb_check_backtrace(bt));
 }
 
 /*