diff --git a/lib/widget/dialog.c b/lib/widget/dialog.c
index c8dddf916..be4adc536 100644
--- a/lib/widget/dialog.c
+++ b/lib/widget/dialog.c
@@ -202,7 +202,7 @@ static int
 dlg_find_widget_callback (const void *a, const void *b)
 {
     const Widget *w = CONST_WIDGET (a);
-    widget_cb_fn f = (widget_cb_fn) b;
+    const widget_cb_fn f = b;
 
     return (w->callback == f) ? 0 : 1;
 }