diff --git a/reference/filesystem/functions/fopen.xml b/reference/filesystem/functions/fopen.xml
index e16bbbf82b..3b193f26d1 100644
--- a/reference/filesystem/functions/fopen.xml
+++ b/reference/filesystem/functions/fopen.xml
@@ -370,6 +370,7 @@ $handle = fopen("ftp://user:password@example.com/somefile.txt", "w");
     <member><function>stream_set_timeout</function></member>
     <member><function>popen</function></member>
     <member><function>stream_context_create</function></member>
+    <member><function>umask</function></member>
    </simplelist>
   </para>
  </refsect1>