diff --git a/Lib/test/test_threadsignals.py b/Lib/test/test_threadsignals.py
index 1c32dfd..bffcb8f 100644
--- a/Lib/test/test_threadsignals.py
+++ b/Lib/test/test_threadsignals.py
@@ -4,6 +4,7 @@
 import thread
 import signal
 import os
+import sys
 from test import test_support
 
 if sys.platform[:3] in ('win', 'os2') or sys.platform=='riscos':