diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 1b091b1..beeb736 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -2016,8 +2016,10 @@
 		On MS-Windows it only checks if the file exists and is not a
 		directory, not if it's really executable.
 		On MS-Windows an executable in the same directory as Vim is
-		always found.  Since this directory is added to $PATH it
-		should also work to execute it |win32-PATH|.
+		normally found.  Since this directory is added to $PATH it
+		should also work to execute it |win32-PATH|.  This can be
+		disabled by setting the $NoDefaultCurrentDirectoryInExePath
+		environment variable.  *NoDefaultCurrentDirectoryInExePath*
 		The result is a Number:
 			1	exists
 			0	does not exist