diff --git a/Lib/idlelib/idle_test/test_zdummy.py b/Lib/idlelib/idle_test/test_zdummy.py
new file mode 100644
--- /dev/null
+++ b/Lib/idlelib/idle_test/test_zdummy.py
@@ -0,0 +1,24 @@
+'''A hack to delete sys.modules['warnings'] after idle tests are run because
+PyShell and run modules monkeypatch it to show warnings 'the Idle way'.
+This causes test_logging to fail. Deleting entry forces re-import.
+But we only want to do this when running test suite with regrtest,
+not when running rests within Idle itself with unittest.
+Both unittest and regrtest sort testcases by file and testcase name.
+'''
+import sys
+import test.support
+import unittest
+
+print('In zdummy, ts.use_resources=', test.support.use_resources)
+def tearDownModule():
+    if test.support.use_resources is not None:  # changed to list by regrtest
+        del sys.modules['_warnings']
+        del sys.modules['warnings']
+    print('in tesrdown')
+
+class Zdummy(unittest.TestCase):
+    def test_zdummy(self):
+        pass
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, exit=False)