-#define EV_RENDER_CONTEXT(context) ((EvRenderContext *) (context))
-#define EV_RENDER_CONTEXT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), EV_TYPE_RENDER_CONTEXT, EvRenderContext))
+#define EV_RENDER_CONTEXT(object) (G_TYPE_CHECK_INSTANCE_CAST((object), EV_TYPE_RENDER_CONTEXT, EvRenderContext))
+#define EV_RENDER_CONTEXT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), EV_TYPE_RENDER_CONTEXT, EvRenderContextClass))