diff --git a/eo_gestion/eo_facture/forms.py b/eo_gestion/eo_facture/forms.py
index 721ef89..df5750a 100644
--- a/eo_gestion/eo_facture/forms.py
+++ b/eo_gestion/eo_facture/forms.py
@@ -201,8 +201,10 @@ class ClientForm(forms.ModelForm):
 class ContratForm(forms.ModelForm):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self.fields['periodicite_debut'].widget.attrs['data-depends-on'] = 'periodicite'
-        self.fields['periodicite_fin'].widget.attrs['data-depends-on'] = 'periodicite'
+        if 'periodicite_debut' in self.fields:
+            self.fields['periodicite_debut'].widget.attrs['data-depends-on'] = 'periodicite'
+        if 'periodicite_fin' in self.fields:
+            self.fields['periodicite_fin'].widget.attrs['data-depends-on'] = 'periodicite'
 
     def clean(self):
         super().clean()