diff --git a/lisp/ox.el b/lisp/ox.el
index 86dce8f7c..07f789361 100644
--- a/lisp/ox.el
+++ b/lisp/ox.el
@@ -6419,7 +6419,7 @@ them."
      ("nb" :default "Innhold")
      ("nn" :default "Innhald")
      ("pl" :html "Spis treści")
-     ("pt_BR" :html "Índice" :utf8 "Índice" :ascii "Indice")
+     ("pt_BR" :html "Índice" :utf-8 "Índice" :ascii "Indice")
      ("ro" :default "Cuprins")
      ("ru" :html "Содержание"
       :utf-8 "Содержание")