diff --git a/hw/arm/microbit.c b/hw/arm/microbit.c
index ef213695bd..72fab429c4 100644
--- a/hw/arm/microbit.c
+++ b/hw/arm/microbit.c
@@ -39,7 +39,7 @@ static void microbit_init(MachineState *machine)
     Object *soc = OBJECT(&s->nrf51);
     Object *i2c = OBJECT(&s->i2c);
 
-    sysbus_init_child_obj(OBJECT(machine), "nrf51", soc, sizeof(s->nrf51),
+    sysbus_init_child_obj(OBJECT(machine), "nrf51", &s->nrf51, sizeof(s->nrf51),
                           TYPE_NRF51_SOC);
     qdev_prop_set_chr(DEVICE(&s->nrf51), "serial0", serial_hd(0));
     object_property_set_link(soc, OBJECT(system_memory), "memory",
@@ -51,7 +51,7 @@ static void microbit_init(MachineState *machine)
      * hack until we implement the nRF51 TWI controller properly and the
      * magnetometer/accelerometer devices.
      */
-    sysbus_init_child_obj(OBJECT(machine), "microbit.twi", i2c,
+    sysbus_init_child_obj(OBJECT(machine), "microbit.twi", &s->i2c,
                           sizeof(s->i2c), TYPE_MICROBIT_I2C);
     object_property_set_bool(i2c, true, "realized", &error_fatal);
     mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(i2c), 0);