diff --git a/hw/misc/lm32_sys.c b/hw/misc/lm32_sys.c
index 060a5bf9b3..9bdb78162f 100644
--- a/hw/misc/lm32_sys.c
+++ b/hw/misc/lm32_sys.c
@@ -44,8 +44,12 @@ enum {
 
 #define MAX_TESTNAME_LEN 16
 
+#define TYPE_LM32_SYS "lm32-sys"
+#define LM32_SYS(obj) OBJECT_CHECK(LM32SysState, (obj), TYPE_LM32_SYS)
+
 struct LM32SysState {
-    SysBusDevice busdev;
+    SysBusDevice parent_obj;
+
     MemoryRegion iomem;
     uint32_t base;
     uint32_t regs[R_MAX];
@@ -104,7 +108,7 @@ static const MemoryRegionOps sys_ops = {
 
 static void sys_reset(DeviceState *d)
 {
-    LM32SysState *s = container_of(d, LM32SysState, busdev.qdev);
+    LM32SysState *s = LM32_SYS(d);
     int i;
 
     for (i = 0; i < R_MAX; i++) {
@@ -115,7 +119,7 @@ static void sys_reset(DeviceState *d)
 
 static int lm32_sys_init(SysBusDevice *dev)
 {
-    LM32SysState *s = FROM_SYSBUS(typeof(*s), dev);
+    LM32SysState *s = LM32_SYS(dev);
 
     memory_region_init_io(&s->iomem, OBJECT(dev), &sys_ops , s,
                           "sys", R_MAX * 4);
@@ -158,7 +162,7 @@ static void lm32_sys_class_init(ObjectClass *klass, void *data)
 }
 
 static const TypeInfo lm32_sys_info = {
-    .name          = "lm32-sys",
+    .name          = TYPE_LM32_SYS,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(LM32SysState),
     .class_init    = lm32_sys_class_init,