diff --git a/os/rt/include/chsys.h b/os/rt/include/chsys.h
index 26c266dd5..e5134d2e8 100644
--- a/os/rt/include/chsys.h
+++ b/os/rt/include/chsys.h
@@ -366,7 +366,7 @@ static inline void chSysUnlock(void) {
      the ready list.*/
   chDbgAssert((ch.rlist.r_queue.p_next == (thread_t *)&ch.rlist.r_queue) ||
               (ch.rlist.r_current->p_prio >= ch.rlist.r_queue.p_next->p_prio),
-              "priority violation, missing reschedule");
+              "priority order violation");
 
   port_unlock();
 }
diff --git a/os/rt/src/chschd.c b/os/rt/src/chschd.c
index e53384b3d..ba73d3562 100644
--- a/os/rt/src/chschd.c
+++ b/os/rt/src/chschd.c
@@ -368,6 +368,10 @@ void chSchWakeupS(thread_t *ntp, msg_t msg) {
 
   chDbgCheckClassS();
 
+  chDbgAssert((ch.rlist.r_queue.p_next == (thread_t *)&ch.rlist.r_queue) ||
+              (ch.rlist.r_current->p_prio >= ch.rlist.r_queue.p_next->p_prio),
+              "priority order violation");
+
   /* Storing the message to be retrieved by the target thread when it will
      restart execution.*/
   ntp->p_u.rdymsg = msg;