diff --git a/src/platforms/posix/work_queue/hrt_thread.c b/src/platforms/posix/work_queue/hrt_thread.c
index 68d980caff..dc3297b006 100644
--- a/src/platforms/posix/work_queue/hrt_thread.c
+++ b/src/platforms/posix/work_queue/hrt_thread.c
@@ -41,6 +41,9 @@
 #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>