diff --git a/helpdesk/models.py b/helpdesk/models.py
index 505b3cba..69ebecbe 100644
--- a/helpdesk/models.py
+++ b/helpdesk/models.py
@@ -715,7 +715,6 @@ class PreSetReply(models.Model):
     queues = models.ManyToManyField(
         Queue,
         blank=True,
-        null=True,
         help_text=_('Leave blank to allow this reply to be used for all '
             'queues, or select those queues you wish to limit this reply to.'),
         )
@@ -757,7 +756,6 @@ class EscalationExclusion(models.Model):
     queues = models.ManyToManyField(
         Queue,
         blank=True,
-        null=True,
         help_text=_('Leave blank for this exclusion to be applied to all '
             'queues, or select those queues you wish to exclude with this '
             'entry.'),
@@ -1061,7 +1059,6 @@ class IgnoreEmail(models.Model):
     queues = models.ManyToManyField(
         Queue,
         blank=True,
-        null=True,
         help_text=_('Leave blank for this e-mail to be ignored on all '
             'queues, or select those queues you wish to ignore this e-mail '
             'for.'),