diff --git a/src/platforms/posix/include/hrt_work.h b/src/platforms/posix/include/hrt_work.h
index 39e53f95d2..4584baf258 100644
--- a/src/platforms/posix/include/hrt_work.h
+++ b/src/platforms/posix/include/hrt_work.h
@@ -46,12 +46,14 @@ void hrt_work_queue_init(void);
 int hrt_work_queue(struct work_s *work, worker_t worker, void *arg, uint32_t usdelay);
 void hrt_work_cancel(struct work_s *work);
 
+static inline void hrt_work_lock(void);
 static inline void hrt_work_lock()
 {
 	//PX4_INFO("hrt_work_lock");
 	sem_wait(&_hrt_work_lock);
 }
 
+static inline void hrt_work_unlock(void);
 static inline void hrt_work_unlock()
 {
 	//PX4_INFO("hrt_work_unlock");