1 files changed, 7 insertions, 0 deletions
diff --git a/error.c b/error.c
index 6a4641fc53..ed2d5220b7 100644
--- a/error.c
+++ b/error.c
@@ -813,6 +813,13 @@ rb_error_frozen(what)
     rb_raise(rb_eTypeError, "can't modify frozen %s", what);
 }
 
+void
+rb_check_frozen(obj)
+    VALUE obj;
+{
+    if (OBJ_FROZEN(obj)) rb_error_frozen(rb_class2name(CLASS_OF(obj)));
+}
+
 static void
 init_syserr()
 {