diff --git a/runtime/doc/usr_41.txt b/runtime/doc/usr_41.txt
index e2d5cfe..97e1d5c 100644
--- a/runtime/doc/usr_41.txt
+++ b/runtime/doc/usr_41.txt
@@ -1289,6 +1289,7 @@
 	popup_filter_yesno()	block until 'y' or 'n' is pressed
 	popup_getoptions()	get current options for a popup
 	popup_getpos()		get actual position and size of a popup
+	popup_findecho()	get window ID for popup used for `:echowindow`
 	popup_findinfo()	get window ID for popup info window
 	popup_findpreview()	get window ID for popup preview window
 	popup_list()		get list of all popup window IDs