diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index e76a1d5..c093d8a 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -887,7 +887,7 @@ gtk_widget_class_init (GtkWidgetClass *klass)
   /**
    * GtkWidget::state-changed:
    * @widget: the object which received the signal.
-   * @state:
+   * @state: the previous state
    */
   widget_signals[STATE_CHANGED] =
     g_signal_new (I_("state-changed"),
