diff --git a/README.md b/README.md
index 739049e..05f00d6 100644
--- a/README.md
+++ b/README.md
@@ -34,9 +34,12 @@ Requires **jey_theme** (declared in `required_apps`).
 
 ### Design machine
 
-Set `"jey_design_mode": 1` in the site's `site_config.json` to enable the editor on
-that site. Without it, the app is inert (production sites just enforce the shipped
-snapshot via jey_theme).
+The editor is enabled automatically wherever this app is installed (design mode
+defaults to ON when `jey_layout` is present). Production sites that only have
+`jey_theme` stay in "always enforce the shipped snapshot" mode.
+
+To override on a specific site, set `"jey_design_mode"` in `site_config.json`
+(`0` to force off, `1` to force on).
 
 ### Installation