-#define PS_DOCUMENT(obj) GTK_CHECK_CAST (obj, PS_TYPE_DOCUMENT, PSDocument)
-#define PS_DOCUMENT_CLASS(klass) GTK_CHECK_CLASS_CAST (klass, PS_TYPE_DOCUMENT, PSDocumentClass)
-#define PS_IS_DOCUMENT(obj) GTK_CHECK_TYPE (obj, PS_TYPE_DOCUMENT)
+#define PS_DOCUMENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), PS_TYPE_DOCUMENT, PSDocument))
+#define PS_DOCUMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), PS_TYPE_DOCUMENT, PSDocumentClass))
+#define PS_IS_DOCUMENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), PS_TYPE_DOCUMENT))