How to use sedlex with dune?

I’m trying to use sedlex as a preprocessor in my project. My dune file is:

(library
 (name cincoson)
 (libraries sedlex)
 (preprocess (pps sedlex)))

When I run dune build , I get:

Entering directory '/Users/itz/src/Ocaml-4.14.0/cincoson'
File "lib/dune", line 4, characters 13-25:
4 |  (preprocess (pps sedlex)))
                 ^^^^^^^^^^^^
Error: No ppx driver were found. It seems that sedlex is not compatible with
Dune. Examples of ppx rewriters that are compatible with Dune are ones using
ocaml-migrate-parsetree, ppxlib or ppx_driver.
File "lib/dune", line 4, characters 18-24:
4 |  (preprocess (pps sedlex)))
                      ^^^^^^
Error: Ppx dependency on a non-ppx library "sedlex". If "sedlex" is in fact a
ppx rewriter library, it should have (kind ppx_rewriter) in its dune file.
-> required by library "cincoson" in _build/default/lib
-> required by
   _build/default/lib/.cincoson.objs/byte/cincoson__Json5_lexing.cmo
-> required by _build/default/lib/cincoson.cma
-> required by alias lib/all
-> required by alias lib/default

The dune file of the example project in the Sedlex repository does (preprocess (pps sedlex.ppx)).

Thanks! That worked.