diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index a72b5218070..f35577c2b6f 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -493,7 +493,9 @@ let
 
     lua-ml = callPackage ../development/ocaml-modules/lua-ml { };
 
-    lwt = callPackage ../development/ocaml-modules/lwt { };
+    lwt = callPackage ../development/ocaml-modules/lwt {
+      ocaml-migrate-parsetree = ocaml-migrate-parsetree-2-1;
+    };
 
     ocaml_lwt = lwt;