diff --git a/rich/ansi.py b/rich/ansi.py
index cff1a049..5fb7e9ea 100644
--- a/rich/ansi.py
+++ b/rich/ansi.py
@@ -1,4 +1,5 @@
 import re
+import sys
 from contextlib import suppress
 from typing import Iterable, NamedTuple