diff --git a/photo21/settings.py b/photo21/settings.py
index 62eb8ec..f6c0917 100644
--- a/photo21/settings.py
+++ b/photo21/settings.py
@@ -157,6 +157,8 @@ USE_L10N = True
 
 USE_TZ = True
 
+DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
+
 # Limit available languages to this subset
 LANGUAGES = [
     ('de', _('German')),