diff --git a/demos/gtk-demo/infobar.c b/demos/gtk-demo/infobar.c
index 2239bbe9b4..402a40bf81 100644
--- a/demos/gtk-demo/infobar.c
+++ b/demos/gtk-demo/infobar.c
@@ -17,7 +17,7 @@ on_bar_response (GtkInfoBar *info_bar,
 
   if (response_id == GTK_RESPONSE_CLOSE)
     {
-      gtk_widget_hide (info_bar);
+      gtk_widget_hide (GTK_WIDGET (info_bar));
       return;
     }