diff --git a/Tools/idle/PyShell.py b/Tools/idle/PyShell.py
index bae4e16d7e0..1f05868ea88 100644
--- a/Tools/idle/PyShell.py
+++ b/Tools/idle/PyShell.py
@@ -157,6 +157,7 @@ def __init__(self, tkconsole):
         self.tkconsole = tkconsole
         locals = sys.modules['__main__'].__dict__
         InteractiveInterpreter.__init__(self, locals=locals)
+        self.save_warnings_filters = None
 
     gid = 0