diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 05f5c9715b..b3aa3cc501 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -556,7 +556,7 @@ class ModelAdmin(BaseModelAdmin):
             raise PermissionDenied
 
         if obj is None:
-            raise Http404(_('%s object with primary key %r does not exist.') % (force_unicode(opts.verbose_name), escape(object_id)))
+            raise Http404(_('%(name)s object with primary key %(key)r does not exist.') % {'name': force_unicode(opts.verbose_name), 'key': escape(object_id)})
 
         if request.method == 'POST' and request.POST.has_key("_saveasnew"):
             return self.add_view(request, form_url='../../add/')
@@ -670,7 +670,7 @@ class ModelAdmin(BaseModelAdmin):
             raise PermissionDenied
 
         if obj is None:
-            raise Http404('%s object with primary key %r does not exist.' % (force_unicode(opts.verbose_name), escape(object_id)))
+            raise Http404(_('%(name)s object with primary key %(key)r does not exist.') % {'name': force_unicode(opts.verbose_name), 'key': escape(object_id)})
 
         # Populate deleted_objects, a data structure of all related objects that
         # will also be deleted.