diff --git a/src/drivers/magnetometer/hmc5883/hmc5883.cpp b/src/drivers/magnetometer/hmc5883/hmc5883.cpp
index 739f4b53c7aef6fdfe35ffc86d0bfc5b719dde9b..4a0b0fb0d0cc38ae2f5a0eb8df9606b807a4861b 100644
--- a/src/drivers/magnetometer/hmc5883/hmc5883.cpp
+++ b/src/drivers/magnetometer/hmc5883/hmc5883.cpp
@@ -1719,7 +1719,7 @@ hmc5883_main(int argc, char *argv[])
 	while ((ch = px4_getopt(argc, argv, "XISR:CT", &myoptind, &myoptarg)) != EOF) {
 		switch (ch) {
 		case 'R':
-			rotation = (enum Rotation)atoi(optarg);
+			rotation = (enum Rotation)atoi(myoptarg);
 			break;
 #if (PX4_I2C_BUS_ONBOARD || PX4_SPIDEV_HMC)