diff --git a/bin/xdg-app-chooser b/bin/xdg-app-chooser
index c793291..16e59de 100755
--- a/bin/xdg-app-chooser
+++ b/bin/xdg-app-chooser
@@ -3,6 +3,10 @@
 """Simple application selector relying on GTK app chooser dialog.
 """
 
+# This doesn't allow to set a default application for a MIME type. Use
+# "xdg-mime default something.desktop mime/type" to change a default.
+# Usually, it will update ~/.config/mimeapps.list.
+
 import argparse
 import sys
 import gi