diff --git a/doc/reference/dune-project/dialect.rst b/doc/reference/dune-project/dialect.rst
index b627a232bdbd..0ac5abbeaa20 100644
--- a/doc/reference/dune-project/dialect.rst
+++ b/doc/reference/dune-project/dialect.rst
@@ -70,8 +70,9 @@ dialect
 
       Configure Merlin to use `<program> <args>...` as READER. Merlin's READER
       is a mechanism to extend Merlin to support OCaml dialects by providing
-      a program that transforms a dialect AST into an OCaml AST. See `merlin/src/extend/extend_protocol.ml <https://github.com/ocaml/merlin/blob/master/src/extend/extend_protocol.ml>`_
-      for the protocol specification.
+      a program that transforms a dialect AST into an OCaml AST.
+
+      .. seealso:: `merlin/src/extend/extend_protocol.ml <https://github.com/ocaml/merlin/blob/4.14-502_preview2/src/extend/extend_protocol.ml>`_ for the protocol specification.
 
       This field is optional.