diff --git a/README.md b/README.md
index 103948c..409087c 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,7 @@ It features:
 + Dynamic workspace support
 + ICCCM/EWMH compliance
 + (Optional) RandR (multi-monitor) support
++ (Optional) Built-in composting manager
 + (Optional) Built-in system tray
 
 Please check out the
diff --git a/exwm.el b/exwm.el
index a972367..bb6b6a7 100644
--- a/exwm.el
+++ b/exwm.el
@@ -36,6 +36,7 @@
 ;; + Dynamic workspace support
 ;; + ICCCM/EWMH compliance
 ;; + (Optional) RandR (multi-monitor) support
+;; + (Optional) Built-in composting manager
 ;; + (Optional) Builtin system tray
 
 ;; Installation & configuration