diff --git a/opam b/opam
index d687f07d..9b1c57b6 100644
--- a/opam
+++ b/opam
@@ -25,6 +25,8 @@ depends: [
   "ocamlbuild" {build}
   "ocamlfind"  {build & >= "1.6.0"}
   "cppo"       {build}
+  "ocaml-migrate-parsetree"
+  "ppx_derivers"
   "ppx_tools"  {>= "4.02.3"}
   "result"
   "ounit"      {test}