diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
index 705948e06109e0..5f5d8527a236fd 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -571,11 +571,10 @@ def test_thread_time(self):
 
         # thread_time() should not include time spend during a sleep
         start = time.thread_time()
-        time.sleep(0.100)
+        time.sleep(0.200)
         stop = time.thread_time()
-        # use 20 ms because thread_time() has usually a resolution of 15 ms
-        # on Windows
-        self.assertLess(stop - start, 0.020)
+        # gh-143528: use 100 ms to support slow CI
+        self.assertLess(stop - start, 0.100)
 
         info = time.get_clock_info('thread_time')
         self.assertTrue(info.monotonic)