diff --git a/runtime/doc/windows.txt b/runtime/doc/windows.txt
index fa94896..d999962 100644
--- a/runtime/doc/windows.txt
+++ b/runtime/doc/windows.txt
@@ -1,4 +1,4 @@
-*windows.txt*   For Vim version 8.1.  Last change: 2019 Aug 04
+*windows.txt*   For Vim version 8.1.  Last change: 2019 Aug 18
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -872,6 +872,7 @@
 settings.  The option is a comma separated list of values:
 	height		maximum height of the popup
 	width		maximum width of the popup
+	highlight	highlight group of the popup (default is Pmenu)
 Example: >
 	:set previewpopup=height:10,width:60