diff --git a/src/drivers/boards/auav-x21/board_config.h b/src/drivers/boards/auav-x21/board_config.h
index 6bc392043f..5e12a12b32 100644
--- a/src/drivers/boards/auav-x21/board_config.h
+++ b/src/drivers/boards/auav-x21/board_config.h
@@ -111,7 +111,6 @@
 
 /* There is no I2C2 so there is not notion of internal / external*/
 #define PX4_I2C_BUS_EXPANSION 1
-#define PX4_I2C_BUS_ONBOARD   1
 #define PX4_I2C_BUS_LED		PX4_I2C_BUS_EXPANSION
 
 /* Devices not on the onboard bus.