diff --git a/docs/devel/qom.rst b/docs/devel/qom.rst
index 42d0dc4f4d..e5fe3597cd 100644
--- a/docs/devel/qom.rst
+++ b/docs/devel/qom.rst
@@ -87,6 +87,14 @@ specific type:
    #define MY_DEVICE(obj) \
       OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
 
+In case the ObjectClass implementation can be built as module a
+module_obj() line must be added to make sure qemu loads the module
+when the object is needed.
+
+.. code-block:: c
+
+   module_obj(TYPE_MY_DEVICE);
+
 Class Initialization
 ====================