diff --git a/include/unistd.h b/include/unistd.h
index d6092e1f22..02e62d2409 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -302,9 +302,7 @@ extern "C"
 pid_t   vfork(void);
 pid_t   getpid(void);
 pid_t   gettid(void);
-#ifdef CONFIG_SCHED_HAVE_PARENT
 pid_t   getppid(void);
-#endif
 void    _exit(int status) noreturn_function;
 unsigned int sleep(unsigned int seconds);
 int     usleep(useconds_t usec);