diff --git a/src/drivers/boards/px4fmu-v5/board_config.h b/src/drivers/boards/px4fmu-v5/board_config.h
index ea787bfa4f..ee7635cb2c 100644
--- a/src/drivers/boards/px4fmu-v5/board_config.h
+++ b/src/drivers/boards/px4fmu-v5/board_config.h
@@ -209,8 +209,8 @@
 
 #define PX4_I2C_BUS_EXPANSION	1
 #define PX4_I2C_BUS_EXPANSION1	2
-#define PX4_I2C_BUS_EXPANSION2	4
-#define PX4_I2C_BUS_EXPANSION3	3
+#define PX4_I2C_BUS_EXPANSION2	3
+#define PX4_I2C_BUS_EXPANSION3	4
 #define PX4_I2C_BUS_LED			PX4_I2C_BUS_EXPANSION
 
 #define BOARD_NUMBER_I2C_BUSES  4