diff --git a/src/modules/commander/commander.cpp b/src/modules/commander/commander.cpp
index 73411bb1c3..e4644c03a3 100644
--- a/src/modules/commander/commander.cpp
+++ b/src/modules/commander/commander.cpp
@@ -47,6 +47,7 @@
 #include <px4_time.h>
 #include <pthread.h>
 #include <stdio.h>
+#include <sys/stat.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
@@ -546,7 +547,7 @@ bool handle_command(struct vehicle_status_s *status_local, const struct safety_s
 				else {
 
 					// Refuse to arm if preflight checks have failed
-					if (!status.hil_state != vehicle_status_s::HIL_STATE_ON && !status.condition_system_sensors_initialized) {
+					if ((!status.hil_state) != vehicle_status_s::HIL_STATE_ON && !status.condition_system_sensors_initialized) {
 						mavlink_log_critical(mavlink_fd, "Arming DENIED. Preflight checks have failed.");
 						cmd_result = VEHICLE_CMD_RESULT_DENIED;			
 						break;