(* TEST
 flags = " -w -a ";
 setup-ocamlc.byte-build-env;
 ocamlc.byte;
 check-ocamlc.byte-output;
*)

(* OK (t = <m:t>) *)
module rec A : sig type t = <m:B.t> end = struct type t = <m:B.t> end
       and B : sig type t = A.t end = struct type t = A.t end;;