diff --git a/gtk/gtkbox.c b/gtk/gtkbox.c
index b8e87094b2..1ca6482e23 100644
--- a/gtk/gtkbox.c
+++ b/gtk/gtkbox.c
@@ -90,10 +90,12 @@
 
 enum {
   PROP_0,
-  PROP_ORIENTATION,
   PROP_SPACING,
   PROP_HOMOGENEOUS,
-  PROP_BASELINE_POSITION
+  PROP_BASELINE_POSITION,
+
+  /* orientable */
+  PROP_ORIENTATION
 };
 
 enum {