diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index b7458134c1..4d0c7c8eee 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -186,6 +186,7 @@ class ModelAdmin(object):
     prepopulated_fields = {}
     filter_vertical = ()
     filter_horizontal = ()
+    inlines = []
 
     def __init__(self, model):
         self.model = model