diff --git a/Doc/lib/libposix.tex b/Doc/lib/libposix.tex
index 0c0339fc85f..540767badfe 100644
--- a/Doc/lib/libposix.tex
+++ b/Doc/lib/libposix.tex
@@ -4,7 +4,7 @@
 \declaremodule{builtin}{posix}
   \platform{Unix}
 \modulesynopsis{The most common \POSIX{} system calls (normally used
-                via module \module{os}).}
+                via module \refmodule{os}).}
 
 
 This module provides access to operating system functionality that is