diff --git a/app/scodoc/sco_formations.py b/app/scodoc/sco_formations.py
index 645606ea..2fc63a34 100644
--- a/app/scodoc/sco_formations.py
+++ b/app/scodoc/sco_formations.py
@@ -222,7 +222,7 @@ def formation_export(
     """Get a formation, with UE, matieres, modules
     in desired format
     """
-    if fmt not in ("xml", "json"):
+    if fmt not in (None, "xml", "json"):
         raise ScoValueError("Format invalide")
     formation = Formation.get_formation(formation_id)
     f_dict = formation_export_dict(