diff --git a/django/contrib/comments/admin.py b/django/contrib/comments/admin.py
index 67c5613a29..81ecc699c7 100644
--- a/django/contrib/comments/admin.py
+++ b/django/contrib/comments/admin.py
@@ -1,5 +1,6 @@
-
 from django.contrib import admin
+from django.contrib.comments.models import Comment, FreeComment
+
 
 class CommentAdmin(admin.ModelAdmin):
     fieldsets = (
diff --git a/django/contrib/flatpages/admin.py b/django/contrib/flatpages/admin.py
index a3f7e9a824..02bbaf6b1a 100644
--- a/django/contrib/flatpages/admin.py
+++ b/django/contrib/flatpages/admin.py
@@ -1,5 +1,7 @@
-
 from django.contrib import admin
+from django.contrib.flatpages.models import FlatPage
+from django.utils.translation import ugettext_lazy as _
+
 
 class FlatPageAdmin(admin.ModelAdmin):
     fieldsets = (
diff --git a/django/contrib/sites/admin.py b/django/contrib/sites/admin.py
index bb5d0cab26..2442c24292 100644
--- a/django/contrib/sites/admin.py
+++ b/django/contrib/sites/admin.py
@@ -1,5 +1,6 @@
-
 from django.contrib import admin
+from django.contrib.sites.models import Site
+
 
 class SiteAdmin(admin.ModelAdmin):
     list_display = ('domain', 'name')