diff --git a/ROMFS/px4fmu_common/init.d-posix/px4-rc.simulator b/ROMFS/px4fmu_common/init.d-posix/px4-rc.simulator
index 4b38c5edf6..1f4693d4c1 100644
--- a/ROMFS/px4fmu_common/init.d-posix/px4-rc.simulator
+++ b/ROMFS/px4fmu_common/init.d-posix/px4-rc.simulator
@@ -8,11 +8,11 @@ if [ "$PX4_SIMULATOR" = "sihsim" ] || [ "$(param show -q SYS_AUTOSTART)" -eq "0"
 
 	echo "INFO  [init] SIH simulator"
 
-	if [ ! -z "${PX4_HOME_LAT}" ]; then
+	if [ -n "${PX4_HOME_LAT}" ]; then
 		param set SIH_LOC_LAT0 ${PX4_HOME_LAT}
 	fi
 
-	if [ ! -z "${PX4_HOME_LON}" ]; then
+	if [ -n "${PX4_HOME_LON}" ]; then
 		param set SIH_LOC_LON0 ${PX4_HOME_LON}
 	fi