diff --git a/py/test/outcome.py b/py/test/outcome.py
index 6994c243e..66a6c2c95 100644
--- a/py/test/outcome.py
+++ b/py/test/outcome.py
@@ -161,6 +161,8 @@ class KeywordDecorator:
         return func 
 
     def __getattr__(self, name):
+        if name[0] == "_":
+            raise AttributeError(name)
         kw = self._keywords.copy()
         kw[name] = True
         return self.__class__(kw, lastname=name)
diff --git a/py/test/testing/test_outcome.py b/py/test/testing/test_outcome.py
index 9c1d5115f..a11691cc4 100644
--- a/py/test/testing/test_outcome.py
+++ b/py/test/testing/test_outcome.py
@@ -76,8 +76,20 @@ def test_importorskip():
         print py.code.ExceptionInfo()
         py.test.fail("spurious skip")
 
+def test_pytest_mark_getattr():
+    from py.__.test.outcome import mark
+    def f(): pass
 
-def test_pytest_mark():
+    mark.hello(f)
+    assert f.hello == True
+
+    mark.hello("test")(f)
+    assert f.hello == "test"
+
+    py.test.raises(AttributeError, "mark._hello")
+    py.test.raises(AttributeError, "mark.__str__")
+
+def test_pytest_mark_call():
     from py.__.test.outcome import mark
     def f(): pass
     mark(x=3)(f)