diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -1315,6 +1315,7 @@ class TestRunner(object):
                 elif code == '~':
                     pass
                 elif code == '.':
+                    # Success is handled automatically by the built-in run().
                     pass
                 elif code == 's':
                     self._result.addSkip(self, msg)