diff --git a/ext/standard/ftok.c b/ext/standard/ftok.c
index d275eba2451..979eb6f3b87 100644
--- a/ext/standard/ftok.c
+++ b/ext/standard/ftok.c
@@ -28,7 +28,7 @@
 #endif
 
 #if HAVE_FTOK
-/* {{{ proto int ftok(string pathname, string proj)
+/* {{{ proto int ftok(string pathname, string proj) U
    Convert a pathname and a project identifier to a System V IPC key */
 PHP_FUNCTION(ftok)
 {