diff --git a/learn-ocaml-client.opam b/learn-ocaml-client.opam
index 437678819..088ff04b4 100644
--- a/learn-ocaml-client.opam
+++ b/learn-ocaml-client.opam
@@ -33,6 +33,7 @@ depends: [
   "lwt_ssl"
   "ocaml" {(>= "4.12") & (< "4.13~")}
   "ocamlfind" {build}
+  "ocaml-migrate-parsetree" {= "1.8.0"}
   "ocp-indent-nlfork"
   "ocplib-json-typed" {>= "0.7"}
   "ocp-ocamlres" {>= "0.4"}
diff --git a/learn-ocaml.opam b/learn-ocaml.opam
index 15f0cbf35..bfd4e2b6e 100644
--- a/learn-ocaml.opam
+++ b/learn-ocaml.opam
@@ -45,6 +45,7 @@ depends: [
   "markup-lwt"
   "ocaml" {(>= "4.12") & (< "4.13~")}
   "ocamlfind" {build}
+  "ocaml-migrate-parsetree" {= "1.8.0"}
   "ocp-indent-nlfork"
   "ocplib-json-typed" {>= "0.7"}
   "ocplib-json-typed-browser" {>= "0.7"}