diff --git a/runtime/doc/usr_41.txt b/runtime/doc/usr_41.txt
index 5f9c8e1..bac064c 100644
--- a/runtime/doc/usr_41.txt
+++ b/runtime/doc/usr_41.txt
@@ -820,6 +820,7 @@
 	setenv()		set an environment variable
 	hostname()		name of the system
 	readfile()		read a file into a List of lines
+	readblob()		read a file into a Blob
 	readdir()		get a List of file names in a directory
 	readdirex()		get a List of file information in a directory
 	writefile()		write a List of lines or Blob into a file