diff --git a/sys/posix/include/semaphore.h b/sys/posix/include/semaphore.h
index 7205679dfa..5340bb80f3 100644
--- a/sys/posix/include/semaphore.h
+++ b/sys/posix/include/semaphore.h
@@ -283,7 +283,7 @@ static inline int sem_trywait(sem_t *sem)
 static inline int sem_getvalue(sem_t *sem, int *sval)
 {
     if (sem != NULL) {
-        *sval = (int)sem->value;
+        *sval = (int)sema_get_value((sema_t *)sem);
         return 0;
     }
     errno = EINVAL;