diff --git a/libraries/AP_HAL_ChibiOS/hwdef/MambaH743v4/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/MambaH743v4/hwdef.dat
index 661909c0d7..f3179a3cb4 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/MambaH743v4/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/MambaH743v4/hwdef.dat
@@ -20,6 +20,7 @@ define CH_CFG_ST_RESOLUTION 16
 
 # leave 1 sectors free
 FLASH_RESERVE_START_KB 384
+env OPTIMIZE -O2
 
 # use last 2 pages for flash storage
 # H743 has 16 pages of 128k each