diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
index b23c19fad61..ec975f82a6f 100644
--- a/Lib/test/test_tempfile.py
+++ b/Lib/test/test_tempfile.py
@@ -762,8 +762,10 @@ def use_closed():
     def test_no_leak_fd(self):
         # Issue #21058: don't leak file descriptor when io.open() fails
         closed = []
+        os_close = os.close
         def close(fd):
             closed.append(fd)
+            os_close(fd)
 
         with mock.patch('os.close', side_effect=close):
             with mock.patch('io.open', side_effect=ValueError):
@@ -1076,8 +1078,10 @@ def roundtrip(input, *args, **kwargs):
         def test_no_leak_fd(self):
             # Issue #21058: don't leak file descriptor when io.open() fails
             closed = []
+            os_close = os.close
             def close(fd):
                 closed.append(fd)
+                os_close(fd)
 
             with mock.patch('os.close', side_effect=close):
                 with mock.patch('io.open', side_effect=ValueError):