diff --git a/pkgs/development/ocaml-modules/mysql/default.nix b/pkgs/development/ocaml-modules/mysql/default.nix
index 4ffef60c4bfc..fc26d8b989c0 100644
--- a/pkgs/development/ocaml-modules/mysql/default.nix
+++ b/pkgs/development/ocaml-modules/mysql/default.nix
@@ -1,4 +1,4 @@
-{stdenv, fetchurl, ocaml, findlib, mysql}:
+{ stdenv, fetchurl, ocaml, findlib, mysql, camlp4 }:
 
 # TODO: la versione stabile da' un errore di compilazione dovuto a
 # qualche cambiamento negli header .h
@@ -23,7 +23,7 @@ stdenv.mkDerivation {
      "--libdir=$out/lib/ocaml/${ocaml_version}/site-lib/mysql"
   ];
 
-  buildInputs = [ocaml findlib mysql.lib ];
+  buildInputs = [ocaml findlib mysql.lib camlp4 ];
 
   createFindlibDestdir = true;