diff --git a/gestion/affich_tools.py b/gestion/affich_tools.py
index ba6bb39e..63e12b00 100644
--- a/gestion/affich_tools.py
+++ b/gestion/affich_tools.py
@@ -31,7 +31,7 @@ else:
 
 try:
     stdout_atty = sys.stdout.isatty()
-except IOError:
+except (IOError, AttributeError):
     stdout_atty = False
 
 def dialog(backtitle,arg,dialogrc='') :