1 files changed, 5 insertions, 1 deletions
diff --git a/archaeological_operations/wizards.py b/archaeological_operations/wizards.py
index fffe34ca7..24c1af45b 100644
--- a/archaeological_operations/wizards.py
+++ b/archaeological_operations/wizards.py
@@ -23,6 +23,7 @@ from django.conf import settings
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.urlresolvers import reverse
 from django.db.models import Max
+from django.http import Http404
 from django.shortcuts import render
 from django.utils.translation import ugettext_lazy as _
 
@@ -149,7 +150,10 @@ class OperationWizard(Wizard):
             data = {}
         if not step:
             step = self.steps.current
-        form = self.get_form_list()[step]
+        try:
+            form = self.get_form_list()[step]
+        except KeyError:
+            raise Http404()
         # manage the dynamic choice of towns
         if step.startswith('towns') and hasattr(form, 'management_form'):
             data['TOWNS'] = self.get_towns()