diff --git a/doc/help-output.txt b/doc/help-output.txt
index 9dda5ee7..a236659b 100644
--- a/doc/help-output.txt
+++ b/doc/help-output.txt
@@ -38,3 +38,4 @@ DMENU command line options:
 	-sync                                  Force dmenu to first read all input data, then show dialog.
 	-async-pre-read [number]               Read several entries blocking before switching to async mode
 		25
+	-w windowid                            Position over window with X11 windowid.