diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 2f70f919d4043f..9894c2647d7c93 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -789,7 +789,9 @@ def test_copy_python_src_ignore(self):
         if not os.path.exists(src_dir):
             self.skipTest(f"cannot access Python source code directory:"
                           f" {src_dir!r}")
-        landmark = os.path.join(src_dir, 'Lib', 'os.py')
+        # Check that the landmark copy_python_src_ignore() expects is available
+        # (Previously we looked for 'Lib\os.py', which is always present on Windows.)
+        landmark = os.path.join(src_dir, 'Modules')
         if not os.path.exists(landmark):
             self.skipTest(f"cannot access Python source code directory:"
                           f" {landmark!r} landmark is missing")