diff --git a/_pytest/main.py b/_pytest/main.py
index 9769f4a2d..de61807ad 100644
--- a/_pytest/main.py
+++ b/_pytest/main.py
@@ -46,7 +46,8 @@ def pytest_addoption(parser):
 
 
 def pytest_namespace():
-    return dict(collect=dict(Item=Item, Collector=Collector, File=File))
+    collect = dict(Item=Item, Collector=Collector, File=File, Session=Session)
+    return dict(collect=collect)
         
 def pytest_configure(config):
     py.test.config = config # compatibiltiy