diff --git a/infoscreen/models.py b/infoscreen/models.py
index 54c6271..18d2b0a 100644
--- a/infoscreen/models.py
+++ b/infoscreen/models.py
@@ -321,7 +321,7 @@ class ExternalImageInfoItem(InfoItem):
 class InfoInstance(models.Model):
     """Class for Info instance in Infoscreen."""
 
-    rotation = models.ForeignKey('Rotation', related_name='instances')
+    rotation = models.ForeignKey('Rotation', related_name='instances', on_delete=models.CASCADE)
     duration = models.FloatField(default=15.0)  # seconds
     # generic relation to some kind of InfoItem
     item_id = models.PositiveIntegerField()
diff --git a/kaehmy/models.py b/kaehmy/models.py
index dcafbf5..237c349 100644
--- a/kaehmy/models.py
+++ b/kaehmy/models.py
@@ -56,7 +56,7 @@ class Comment(CommentParent):
         verbose_name_plural = _('Kaehmykommentit')
 
     message = models.TextField(_('Message'))
-    parent = models.ForeignKey('CommentParent', related_name='messages')
+    parent = models.ForeignKey('CommentParent', related_name='messages', on_delete=models.CASCADE)
 
 
 class Application(CommentParent):
diff --git a/webapp/models.py b/webapp/models.py
index 169e5a6..7549942 100644
--- a/webapp/models.py
+++ b/webapp/models.py
@@ -138,7 +138,7 @@ class Role(PresetRole):
 
     start_date = models.DateField(_('Start date'))
     end_date = models.DateField(_('End date'))
-    official = models.ForeignKey('Official', related_name='roles')
+    official = models.ForeignKey('Official', related_name='roles', on_delete=models.CASCADE)
 
 
 class Official(User):
diff --git a/webapp/views.py b/webapp/views.py
index fa6d43d..e663a58 100644
--- a/webapp/views.py
+++ b/webapp/views.py
@@ -40,7 +40,7 @@ def login_view(request, *args, **kwargs):
 
     # user got here by a get request
     user = request.user
-    if user.is_authenticated():
+    if user.is_authenticated:
         # user shoud not be here authenticated with get but get rid if is
         return redirect("/")
     return render(request, "login.html", {})