diff --git a/qemu/include/qapi/qmp/qobject.h b/qemu/include/qapi/qmp/qobject.h
index 9e945bab..609b0245 100644
--- a/qemu/include/qapi/qmp/qobject.h
+++ b/qemu/include/qapi/qmp/qobject.h
@@ -65,9 +65,8 @@ struct QObject {
 QEMU_BUILD_BUG_MSG(QTYPE__MAX != 7,
                    "The QTYPE_CAST_TO_* list needs to be extended");
 
-#define qobject_to(type, obj) ({ \
-    QObject *_tmp = qobject_check_type(obj, glue(QTYPE_CAST_TO_, type)); \
-    _tmp ? container_of(_tmp, type, base) : (type *)NULL; })
+#define qobject_to(type, obj)                                       \
+    ((type *)qobject_check_type(obj, glue(QTYPE_CAST_TO_, type)))
 
 /* Initialize an object to default values */
 static inline void qobject_init(QObject *obj, QType type)
diff --git a/qemu/qobject/qobject.c b/qemu/qobject/qobject.c
index 6edaacb9..ce13affd 100644
--- a/qemu/qobject/qobject.c
+++ b/qemu/qobject/qobject.c
@@ -15,6 +15,15 @@
 #include "qapi/qmp/qlist.h"
 #include "qapi/qmp/qstring.h"
 
+QEMU_BUILD_BUG_MSG(
+    offsetof(QNull, base) != 0 ||
+    offsetof(QNum, base) != 0 ||
+    offsetof(QString, base) != 0 ||
+    offsetof(QDict, base) != 0 ||
+    offsetof(QList, base) != 0 ||
+    offsetof(QBool, base) != 0,
+    "base qobject must be at offset 0");
+
 static void (*qdestroy[QTYPE__MAX])(QObject *) = {
     NULL,               /* No such object exists */
     NULL,              /* qnull_ is indestructible */