diff --git a/docs/django-admin.txt b/docs/django-admin.txt
index c68f2d7ba8..ab9a05052d 100644
--- a/docs/django-admin.txt
+++ b/docs/django-admin.txt
@@ -95,6 +95,11 @@ DO NOT USE THIS SERVER IN A PRODUCTION SETTING.
 The development server automatically reloads Python code for each request, as
 needed. You don't need to restart the server for code changes to take effect.
 
+When you start the server, and each time you change Python code while the
+server is running, the server will validate all of your installed models. (See
+the "validate" option below.) If the validator finds errors, it will print
+them to standard output, but it won't stop the server.
+
 You can run as many servers as you want, as long as they're on separate ports.
 Just execute ``django-admin.py runserver`` more than once.