diff --git a/libraries/AP_HAL_ChibiOS/hwdef/OmnibusNanoV6/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/OmnibusNanoV6/hwdef.dat
index 459f376692..a0b5193180 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/OmnibusNanoV6/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/OmnibusNanoV6/hwdef.dat
@@ -44,8 +44,9 @@ PB10 I2C2_SCL I2C2 PULLUP
 PB11 I2C2_SDA I2C2 PULLUP
 
 # I2C1 on PPM / PB9 pads of V6.x board revision
-PB8 I2C1_SCL I2C1 PULLUP
-PB9 I2C1_SDA I2C1 PULLUP
+# On ALT config as it interferes with 6.0 revisions
+PB8 I2C1_SCL I2C1 PULLUP ALT(1)
+PB9 I2C1_SDA I2C1 PULLUP ALT(1)
 
 # use RX3 / TX3 pins as USART3 = SERIAL4 in BRD_ALT_CONFIG = 1
 PB10 USART3_TX USART3 ALT(1)