diff --git a/django/contrib/comments/models.py b/django/contrib/comments/models.py
index 7dd4f81..114b115 100644
--- a/django/contrib/comments/models.py
+++ b/django/contrib/comments/models.py
@@ -8,6 +8,7 @@ from django.db import models
 from django.core import urlresolvers
 from django.utils.translation import ugettext_lazy as _
 from django.conf import settings
+from django.contrib import comments
 
 COMMENT_MAX_LENGTH = getattr(settings,'COMMENT_MAX_LENGTH',3000)
 
@@ -166,7 +167,7 @@ class CommentFlag(models.Model):
     if you want rating look elsewhere.
     """
     user      = models.ForeignKey(User, verbose_name=_('user'), related_name="comment_flags")
-    comment   = models.ForeignKey(Comment, verbose_name=_('comment'), related_name="flags")
+    comment   = models.ForeignKey(comments.get_model(), verbose_name=_('comment'), related_name="flags")
     flag      = models.CharField(_('flag'), max_length=30, db_index=True)
     flag_date = models.DateTimeField(_('date'), default=None)