diff --git a/include/qom/object.h b/include/qom/object.h
index 4cd84998c2997524c0adf69811e1fe86641a2ce6..3626ae3c65582bdaa1ce4712d2dfd986a615b279 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -567,7 +567,7 @@ struct Object
  */
 #define DECLARE_INSTANCE_CHECKER(InstanceType, OBJ_NAME, TYPENAME) \
     static inline G_GNUC_UNUSED InstanceType * \
-    OBJ_NAME(void *obj) \
+    OBJ_NAME(const void *obj) \
     { return OBJECT_CHECK(InstanceType, obj, TYPENAME); }
 
 /**
@@ -584,11 +584,11 @@ struct Object
  */
 #define DECLARE_CLASS_CHECKERS(ClassType, OBJ_NAME, TYPENAME) \
     static inline G_GNUC_UNUSED ClassType * \
-    OBJ_NAME##_GET_CLASS(void *obj) \
+    OBJ_NAME##_GET_CLASS(const void *obj) \
     { return OBJECT_GET_CLASS(ClassType, obj, TYPENAME); } \
     \
     static inline G_GNUC_UNUSED ClassType * \
-    OBJ_NAME##_CLASS(void *klass) \
+    OBJ_NAME##_CLASS(const void *klass) \
     { return OBJECT_CLASS_CHECK(ClassType, klass, TYPENAME); }
 
 /**