diff --git a/src/agenda_culturel/models.py b/src/agenda_culturel/models.py
index 104a126..5214365 100644
--- a/src/agenda_culturel/models.py
+++ b/src/agenda_culturel/models.py
@@ -12,6 +12,8 @@ from datetime import datetime
 class Category(models.Model):
 
     default_name = "Sans catégorie"
+    default_alt_name = "Événements non catégorisés"
+    default_codename = "∅"
     default_css_class = "cat-nocat"
     default_color = "#aaaaaa"
 
@@ -46,6 +48,14 @@ class Category(models.Model):
 
         super(Category, self).save(*args, **kwargs)
 
+
+    def get_default_category_id():
+        default, created = Category.objects.get_or_create(name=Category.default_name,
+            alt_name=Category.default_alt_name,
+            codename=Category.default_codename,
+            color=Category.default_color)
+        return default.id
+
     def css_class(self):
         return "cat-" + str(self.id)
 
@@ -71,7 +81,7 @@ class Event(models.Model):
 
     status = models.CharField(_("Status"), max_length=20, choices=STATUS.choices, default=STATUS.PUBLISHED)
 
-    category = models.ForeignKey(Category, verbose_name=_('Category'), help_text=_('Category of the event'), null=True, on_delete=models.SET_NULL)
+    category = models.ForeignKey(Category, verbose_name=_('Category'), help_text=_('Category of the event'), default=Category.get_default_category_id(), on_delete=models.SET_DEFAULT)
 
     start_day = models.DateField(verbose_name=_('Day of the event'), help_text=_('Day of the event'))
     start_time = models.TimeField(verbose_name=_('Starting time'), help_text=_('Starting time'), blank=True, null=True)