diff --git a/runtime/doc/usr_41.txt b/runtime/doc/usr_41.txt
index e9e16fe..a9a1fcd 100644
--- a/runtime/doc/usr_41.txt
+++ b/runtime/doc/usr_41.txt
@@ -904,6 +904,7 @@
 	getfperm()		get the permissions of a file
 	setfperm()		set the permissions of a file
 	getftype()		get the kind of a file
+	isabsolutepath()	check if a path is absolute
 	isdirectory()		check if a directory exists
 	getfsize()		get the size of a file
 	getcwd()		get the current working directory