diff --git a/app/core/gimpresource.h b/app/core/gimpresource.h
index 9f08a11c3c..1de905f451 100644
--- a/app/core/gimpresource.h
+++ b/app/core/gimpresource.h
@@ -20,21 +20,13 @@
 #include "gimpviewable.h"
 
 
-#define GIMP_TYPE_RESOURCE            (gimp_resource_get_type ())
-#define GIMP_RESOURCE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_RESOURCE, GimpResource))
-#define GIMP_RESOURCE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_RESOURCE, GimpResourceClass))
-#define GIMP_IS_RESOURCE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_RESOURCE))
-#define GIMP_IS_RESOURCE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_RESOURCE))
-#define GIMP_RESOURCE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_RESOURCE, GimpResourceClass))
+#define GIMP_TYPE_RESOURCE (gimp_resource_get_type ())
+G_DECLARE_DERIVABLE_TYPE (GimpResource,
+                          gimp_resource,
+                          GIMP, RESOURCE,
+                          GimpViewable)
 
 
-typedef struct _GimpResourceClass GimpResourceClass;
-
-struct _GimpResource
-{
-  GimpViewable parent_instance;
-};
-
 struct _GimpResourceClass
 {
   GimpViewableClass parent_class;