diff --git a/src/modules/commander/state_machine_helper.cpp b/src/modules/commander/state_machine_helper.cpp
index 1e892ed77f..9178bcc5ab 100644
--- a/src/modules/commander/state_machine_helper.cpp
+++ b/src/modules/commander/state_machine_helper.cpp
@@ -351,6 +351,23 @@ int hil_state_transition(hil_state_t new_state, int status_pub, struct vehicle_s
 							return 1;
 						}
 
+						/* skip serial ports */
+						if (!strncmp("tty", direntry-d_name, 3)) {
+							continue;
+						}
+						/* skip mtd devices */
+						if (!strncmp("mtd", direntry-d_name, 3)) {
+							continue;
+						}
+						/* skip ram devices */
+						if (!strncmp("ram", direntry-d_name, 3)) {
+							continue;
+						}
+						/* skip mavlink */
+						if (!strcmp("mavlink", direntry-d_name)) {
+							continue;
+						}
+
 						int block_ret = ::ioctl(sensfd, DEVIOCSPUBBLOCK, 1);
 						close(sensfd);
 
@@ -359,8 +376,6 @@ int hil_state_transition(hil_state_t new_state, int status_pub, struct vehicle_s
 
 					closedir(d);
 
-					warnx("directory listing ok (FS mounted and readable)");
-
 				} else {
 					/* failed opening dir */
 					warnx("FAILED LISTING DEVICE ROOT DIRECTORY");