diff --git a/src/core/timeouts.c b/src/core/timeouts.c
index fcba0a1a..e2dc0fc7 100644
--- a/src/core/timeouts.c
+++ b/src/core/timeouts.c
@@ -360,7 +360,6 @@ sys_check_timeouts(void)
   }
 }
 
-#if NO_SYS
 /** Set back the timestamp of the last call to sys_check_timeouts()
  * This is necessary if sys_check_timeouts() hasn't been called for a long
  * time (e.g. while saving energy) to prevent all timer functions of that
@@ -371,7 +370,6 @@ sys_restart_timeouts(void)
 {
   timeouts_last_time = sys_now();
 }
-#endif /* NO_SYS */
 
 /** Return the time left before the next timeout is due. If no timeouts are
  * enqueued, returns 0xffffffff
diff --git a/src/include/lwip/timeouts.h b/src/include/lwip/timeouts.h
index 4988b151..c9b93aa0 100644
--- a/src/include/lwip/timeouts.h
+++ b/src/include/lwip/timeouts.h
@@ -103,9 +103,9 @@ void sys_timeout(u32_t msecs, sys_timeout_handler handler, void *arg);
 #endif /* LWIP_DEBUG_TIMERNAMES */
 
 void sys_untimeout(sys_timeout_handler handler, void *arg);
+void sys_restart_timeouts(void);
 #if NO_SYS
 void sys_check_timeouts(void);
-void sys_restart_timeouts(void);
 u32_t sys_timeouts_sleeptime(void);
 #else /* NO_SYS */
 void sys_timeouts_mbox_fetch(sys_mbox_t *mbox, void **msg);