diff --git a/drivers/i2c/i2c-slave-testunit.c b/drivers/i2c/i2c-slave-testunit.c
index a49642bbae4b70..a5dcbc3c2c141a 100644
--- a/drivers/i2c/i2c-slave-testunit.c
+++ b/drivers/i2c/i2c-slave-testunit.c
@@ -118,7 +118,7 @@ static int i2c_slave_testunit_slave_cb(struct i2c_client *client,
 			queue_delayed_work(system_long_wq, &tu->worker,
 					   msecs_to_jiffies(10 * tu->regs[TU_REG_DELAY]));
 		}
-		fallthrough;
+		break;
 
 	case I2C_SLAVE_WRITE_REQUESTED:
 		memset(tu->regs, 0, TU_NUM_REGS);