diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c
index 8a30d0559d60..617333343ca0 100644
--- a/drivers/net/mctp/mctp-i2c.c
+++ b/drivers/net/mctp/mctp-i2c.c
@@ -244,7 +244,10 @@ static int mctp_i2c_slave_cb(struct i2c_client *client,
 
 	switch (event) {
 	case I2C_SLAVE_READ_REQUESTED:
+	case I2C_SLAVE_READ_PROCESSED:
+		/* MCTP I2C transport only uses writes */
 		midev->rx_pos = 0;
+		*val = 0xff;
 		break;
 	case I2C_SLAVE_WRITE_RECEIVED:
 		if (midev->rx_pos < MCTP_I2C_BUFSZ) {