Issue #17919: add missing import of USHRT_MAX
diff --git a/Lib/test/test_devpoll.py b/Lib/test/test_devpoll.py
index c7bacf8..819d9dc 100644
--- a/Lib/test/test_devpoll.py
+++ b/Lib/test/test_devpoll.py
@@ -4,6 +4,7 @@
 
 import os, select, random, unittest, sys
 from test.support import TESTFN, run_unittest
+from _testcapi import USHRT_MAX
 
 try:
     select.devpoll