diff --git a/sim_disk.c b/sim_disk.c
index 946ea5eb..d19cf034 100644
--- a/sim_disk.c
+++ b/sim_disk.c
@@ -6615,8 +6615,13 @@ if (info->flag) {        /* zap type */
                     (sector_size != sim_fread (sector_data, 1, sector_size, container))   ||
                     (0 != memcmp (sector_data, zero_sector, sector_size)))
                     break;
+                if ((sim_switches & SWMASK ('Z'))       &&
+                    (0 == (container_size % 1024*1024)))
+                    sim_messagef (SCPE_OK, "Trimming trailing zero containing blocks at lbn: %u          \r", (uint32)(container_size / sector_size));
                 container_size -= sector_size;
                 }
+            if (sim_switches & SWMASK ('Z'))
+                sim_messagef (SCPE_OK, "Last zero containing block found at lbn: %u          \n", (uint32)(container_size / sector_size));
             free (sector_data);
             free (zero_sector);
             (void)sim_set_fsize (container, (t_addr)container_size);