diff --git a/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F412/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F412/hwdef.dat
index 040ab4caac..17872ef552 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F412/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F412/hwdef.dat
@@ -117,9 +117,6 @@ define HAL_PERIPH_ENABLE_BARO
 define HAL_PERIPH_ENABLE_RC_OUT
 define HAL_PERIPH_ENABLE_NOTIFY
 
-# use the app descriptor needed by MissionPlanner for CAN upload
-env APP_DESCRIPTOR MissionPlanner
-
 # reserve 256 bytes for comms between app and bootloader
 RAM_RESERVE_START 256
 
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F9P/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F9P/hwdef.dat
index a709ddc0fe..8157bb92d6 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F9P/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/Sierra-F9P/hwdef.dat
@@ -148,9 +148,6 @@ PC11 SDIO_D3 SDIO
 PB15 SDIO_CK SDIO
 PD2 SDIO_CMD SDIO
 
-# use the app descriptor needed by MissionPlanner for CAN upload
-env APP_DESCRIPTOR MissionPlanner
-
 # reserve 256 bytes for comms between app and bootloader
 RAM_RESERVE_START 256