diff --git a/tests/test_core_file_fills_declaration.py b/tests/test_core_file_fills_declaration.py
index b62e83506..1f4ee4309 100644
--- a/tests/test_core_file_fills_declaration.py
+++ b/tests/test_core_file_fills_declaration.py
@@ -174,7 +174,8 @@ class AMissingDataDirectoryFailsTheRun(unittest.TestCase):
                 offline=True,
             )
         self.assertEqual(gp._MISSING_DATA_DIRS, {"assets"})
-        with mock.patch.object(gp, "_main", lambda held: None), \
+        # main() starts each run with no notices, so the run itself records it.
+        with mock.patch.object(gp, "_main", lambda held: gp._MISSING_DATA_DIRS.add("assets")), \
                 contextlib.redirect_stderr(io.StringIO()), \
                 self.assertRaises(SystemExit) as stop:
             gp.main()