diff --git a/py/test/rsession/testing/test_webjs.py b/py/test/rsession/testing/test_webjs.py
index 58e68f604..f9c9fa3a0 100644
--- a/py/test/rsession/testing/test_webjs.py
+++ b/py/test/rsession/testing/test_webjs.py
@@ -43,7 +43,7 @@ def test_html_loaded():
     assert str(body.childNodes[1].nodeName) == 'A'
 
 def test_set_msgbox():
-    py.test.skip
+    py.test.skip("not implemented in genjs")
     msgbox = dom.window.document.getElementById('messagebox')
     assert len(msgbox.childNodes) == 0
     webjs.set_msgbox('foo', 'bar')