diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 599f903..880ab0d 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 9.1.  Last change: 2025 Jan 23
+*options.txt*	For Vim version 9.1.  Last change: 2025 Jan 26
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -8501,6 +8501,11 @@
 	When on, uses |highlight-guifg| and |highlight-guibg| attributes in
 	the terminal (thus using 24-bit color).
 
+	Will automatically be enabled, if Vim detects that it runs in a
+	capable terminal (when the terminal supports the RGB terminfo
+	capability or when the number of colors |t_Co| supported by the
+	terminal is 0x1000000, e.g. with $TERM=xterm-direct).
+
 	Requires a ISO-8613-3 compatible terminal.  If setting this option
 	does not work (produces a colorless UI) reading |xterm-true-color|
 	might help.
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index f77499a..e2243f6 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2025 Jan 25
+*version9.txt*  For Vim version 9.1.  Last change: 2025 Jan 26
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41628,6 +41628,8 @@
 - New option value "nosort" for 'completeopt'
 - add |dist#vim9#Launch()| and |dist#vim9#Open()| to the |vim-script-library|
   and decouple it from |netrw|
+- 'termguicolors' is automatically enabled if the terminal supports the RGB
+  terminfo capability or supports 0x1000000 colors
 
 							*added-9.2*
 Added ~