diff --git a/arch/sim/src/sim/up_rptun.c b/arch/sim/src/sim/up_rptun.c
index 8af25e7cf42..fcbc28acd69 100644
--- a/arch/sim/src/sim/up_rptun.c
+++ b/arch/sim/src/sim/up_rptun.c
@@ -171,16 +171,20 @@ void up_rptun_loop(void)
     {
       if (dev->shmem != NULL)
         {
+          bool diff = false;
+
           if (dev->master && dev->seq != dev->shmem->seqs)
             {
               dev->seq = dev->shmem->seqs;
+              diff = true;
             }
           else if (!dev->master && dev->seq != dev->shmem->seqm)
             {
               dev->seq = dev->shmem->seqm;
+              diff = true;
             }
 
-          if (dev->callback != NULL)
+          if (diff && dev->callback != NULL)
             {
               dev->callback(dev->arg, RPTUN_NOTIFY_ALL);
             }