diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index fea68163b3a..5f33d3975ed 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -1100,6 +1100,7 @@ def test_islice(self):
         it = islice(it, 1)
         self.assertIsNotNone(wr())
         list(it) # exhaust the iterator
+        support.gc_collect()
         self.assertIsNone(wr())
 
     def test_takewhile(self):