diff --git a/etc/MiniGUI.cfg b/etc/MiniGUI.cfg
index 95ff8089..09efbdc0 100644
--- a/etc/MiniGUI.cfg
+++ b/etc/MiniGUI.cfg
@@ -48,6 +48,11 @@ wallpaper_pattern_size=full
 # wallpaper_pattern_size=octant
 # wallpaper_pattern_size=empty
 # wallpaper_pattern_size=32x32
+
+# The shared object name of the default compositor. If it is not defined
+# or failed to load, MiniGUI will use the built-in fallback compositor.
+# The equivalent environment variable: MG_DEF_COMPOSITOR_SO
+# def_compositor_so=
 #}}
 
 #{{ifdef _MGGAL_DRM