diff --git a/shell/ev-sidebar.c b/shell/ev-sidebar.c
index bd45f261..23d51f99 100644
--- a/shell/ev-sidebar.c
+++ b/shell/ev-sidebar.c
@@ -208,7 +208,7 @@ ev_sidebar_menu_position_under (GtkMenu  *menu,
 	GtkWidget *widget;
 
 	g_return_if_fail (GTK_IS_BUTTON (user_data));
-	g_return_if_fail (gtk_widget_get_has_window (GTK_WIDGET (user_data)));
+	g_return_if_fail (!gtk_widget_get_has_window (GTK_WIDGET (user_data)));
 
 	widget = GTK_WIDGET (user_data);