diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 5a72e21..4ad6b3d 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2025 Mar 30
+*builtin.txt*	For Vim version 9.1.  Last change: 2025 Apr 18
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -8158,7 +8158,8 @@
 <		      1.41
 
 		You will get an overflow error |E1510|, when the field-width
-		or precision will result in a string longer than 6400 chars.
+		or precision will result in a string longer than 1 MB
+		(1024*1024 = 1048576) chars.
 
 							*E1500*
 		You cannot mix positional and non-positional arguments: >