diff --git a/src/platforms/posix/px4_layer/px4_posix_impl.cpp b/src/platforms/posix/px4_layer/px4_posix_impl.cpp
index f12fd44d68..c77fe760b8 100644
--- a/src/platforms/posix/px4_layer/px4_posix_impl.cpp
+++ b/src/platforms/posix/px4_layer/px4_posix_impl.cpp
@@ -40,6 +40,7 @@
 #include <px4_defines.h>
 #include <px4_middleware.h>
 #include <px4_workqueue.h>
+#include <px4_defines.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <signal.h>
@@ -49,9 +50,6 @@
 #include "hrt_work.h"
 #include <drivers/drv_hrt.h>
 #include "px4_time.h"
-#ifdef __PX4_LINUX
-#define _GNU_SOURCE
-#endif
 #include <pthread.h>
 
 extern pthread_t _shell_task_id;
diff --git a/src/platforms/posix/px4_layer/px4_posix_tasks.cpp b/src/platforms/posix/px4_layer/px4_posix_tasks.cpp
index f4a291341d..a220b88c67 100644
--- a/src/platforms/posix/px4_layer/px4_posix_tasks.cpp
+++ b/src/platforms/posix/px4_layer/px4_posix_tasks.cpp
@@ -38,6 +38,7 @@
  */
 
 #include <px4_log.h>
+#include <px4_defines.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -48,9 +49,6 @@
 #include <sched.h>
 #include <unistd.h>
 #include <string.h>
-#ifdef __PX4_LINUX
-#define _GNU_SOURCE
-#endif
 #include <pthread.h>
 
 #include <sys/stat.h>
diff --git a/src/platforms/posix/work_queue/hrt_thread.c b/src/platforms/posix/work_queue/hrt_thread.c
index dc3297b006..68d980caff 100644
--- a/src/platforms/posix/work_queue/hrt_thread.c
+++ b/src/platforms/posix/work_queue/hrt_thread.c
@@ -41,9 +41,6 @@
 #include <px4_config.h>
 #include <px4_defines.h>
 #include <px4_posix.h>
-#ifdef __PX4_LINUX
-#define _GNU_SOURCE
-#endif
 #include <pthread.h>
 #include <stdint.h>
 #include <signal.h>
diff --git a/src/platforms/posix/work_queue/work_thread.c b/src/platforms/posix/work_queue/work_thread.c
index f8ff2a52fd..2050ad51e6 100644
--- a/src/platforms/posix/work_queue/work_thread.c
+++ b/src/platforms/posix/work_queue/work_thread.c
@@ -45,9 +45,6 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <queue.h>
-#ifdef __PX4_LINUX
-#define _GNU_SOURCE
-#endif
 #include <pthread.h>
 #include <px4_workqueue.h>
 #include <drivers/drv_hrt.h>