diff --git a/src/rt-migrate-test/rt-migrate-test.c b/src/rt-migrate-test/rt-migrate-test.c
index d7b68dd..0a0bb77 100644
--- a/src/rt-migrate-test/rt-migrate-test.c
+++ b/src/rt-migrate-test/rt-migrate-test.c
@@ -20,9 +20,6 @@
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdio.h>
 #ifndef __USE_XOPEN2K
 # define __USE_XOPEN2K
diff --git a/src/sched_deadline/cyclicdeadline.c b/src/sched_deadline/cyclicdeadline.c
index f530488..fd78d31 100644
--- a/src/sched_deadline/cyclicdeadline.c
+++ b/src/sched_deadline/cyclicdeadline.c
@@ -1,6 +1,3 @@
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <pthread.h>
 #include <stdarg.h>
 #include <stdlib.h>
diff --git a/src/sched_deadline/deadline_test.c b/src/sched_deadline/deadline_test.c
index 2794730..196dfec 100644
--- a/src/sched_deadline/deadline_test.c
+++ b/src/sched_deadline/deadline_test.c
@@ -29,9 +29,6 @@
  *    Look for "simple_test"
  *
  */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <pthread.h>
 #include <stdarg.h>
 #include <stdlib.h>