diff -ur vcontrold/common.c.orig vcontrold/common.c
--- vcontrold/common.c.orig	2017-11-04 09:33:01.309352203 +0100
+++ vcontrold/common.c	2017-11-04 09:52:44.019193686 +0100
@@ -2,6 +2,9 @@
  * Testprogramm fuer Vito- Abfrage
  *  */
 /* $Id: common.c 26 2008-03-20 20:56:09Z marcust $ */
+
+#define _GNU_SOURCE
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
diff -ur vcontrold/socket.c.orig vcontrold/socket.c
--- vcontrold/socket.c.orig	2017-11-04 09:33:01.312352182 +0100
+++ vcontrold/socket.c	2017-11-04 09:52:35.549252116 +0100
@@ -1,6 +1,8 @@
 /* socket.c */
 /* $Id: socket.c 13 2008-03-02 13:13:41Z marcust $ */
 
+#define _GNU_SOURCE
+
 #include <sys/time.h>
 #include <time.h>
 #include <errno.h>
diff -ur vcontrold/vsim.c vcontrold/vsim.c
--- vcontrold/vsim.c.orig	2017-11-04 09:33:01.305352231 +0100
+++ vcontrold/vsim.c	2017-11-04 09:52:26.808312412 +0100
@@ -1,3 +1,5 @@
+#define _GNU_SOURCE
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <ctype.h>