Nix dllcamlzip.so not found

Whenever I add camlzipto my dependencies in a dune file and try to run dune utop I get the following error:

File "_none_", line 1:           
Error: I/O error: dllcamlzip.so: No such file or directory

I am using Nix as a package manager. Has anyone encountered this or does anyone know how I could find out where the problem lies?

my shell.nix:

with import <nixpkgs> { };
mkShell {
  nativeBuildInputs = [
    ocamlPackages.camlzip
    ocamlPackages.utop
  ];
}

I’d try it in a raw toplevel, e.g.

#use "topfind";;
#require "camlzip";;
#show Gzip ;;
module Gzip :
  sig
    type in_channel
    val open_in : string -> in_channel
.......