Index: gtk/gtkaction.c
===================================================================
--- gtk/gtkaction.c	(revision 22144)
+++ gtk/gtkaction.c	(working copy)
@@ -220,7 +220,8 @@ gtk_action_class_init (GtkActionClass *k
 							P_("The label used for menu items and buttons "
 							   "that activate this action."),
 							NULL,
-							GTK_PARAM_READWRITE));
+							GTK_PARAM_READWRITE |
+							G_PARAM_CONSTRUCT));
   g_object_class_install_property (gobject_class,
 				   PROP_SHORT_LABEL,
 				   g_param_spec_string ("short-label",
@@ -234,7 +235,8 @@ gtk_action_class_init (GtkActionClass *k
 							P_("Tooltip"),
 							P_("A tooltip for this action."),
 							NULL,
-							GTK_PARAM_READWRITE));
+							GTK_PARAM_READWRITE |
+							G_PARAM_CONSTRUCT));
   g_object_class_install_property (gobject_class,
 				   PROP_STOCK_ID,
 				   g_param_spec_string ("stock-id",
@@ -242,7 +244,8 @@ gtk_action_class_init (GtkActionClass *k
 							P_("The stock icon displayed in widgets representing "
 							   "this action."),
 							NULL,
-							GTK_PARAM_READWRITE));
+							GTK_PARAM_READWRITE |
+							G_PARAM_CONSTRUCT));
   /**
    * GtkAction:gicon:
    *
