diff --git a/myocamlbuild.ml b/myocamlbuild.ml
index 5f27fb6..a5e0641 100644
--- a/myocamlbuild.ml
+++ b/myocamlbuild.ml
@@ -30,16 +30,25 @@ let () =
              (* Use -linkpkg for creating toplevels *)
              flag ["ocaml"; "link"; "toplevel"] & A"-linkpkg";
 
-             (* Optcomp *)
-             flag ["ocaml"; "compile"; "pa_optcomp"] & S[A"-ppopt"; A "syntax/pa_optcomp.cmo"];
-             flag ["ocaml"; "ocamldep"; "pa_optcomp"] & S[A"-ppopt"; A "syntax/pa_optcomp.cmo"];
-             flag ["ocaml"; "doc"; "pa_optcomp"] & S[A"-ppopt"; A "syntax/pa_optcomp.cmo"];
-             dep ["ocaml"; "ocamldep"; "pa_optcomp"] ["syntax/pa_optcomp.cmo"];
-
              let env = BaseEnvLight.load () in
              let path = BaseEnvLight.var_get "compiler_libs" env in
              let stdlib = BaseEnvLight.var_get "standard_library" env in
 
+             let findlib_version = BaseEnvLight.var_get "findlib_version" env in
+             let findlib_version =
+               Scanf.sscanf findlib_version "%d.%d" (Printf.sprintf "findlib_version=(%d, %d)")
+             in
+
+             (* Optcomp *)
+             let args =
+               S[A"-ppopt"; A"syntax/pa_optcomp.cmo";
+                 A"-ppopt"; A"-let"; A"-ppopt"; A findlib_version]
+             in
+             flag ["ocaml"; "compile"; "pa_optcomp"] args;
+             flag ["ocaml"; "ocamldep"; "pa_optcomp"] args;
+             flag ["ocaml"; "doc"; "pa_optcomp"] args;
+             dep ["ocaml"; "ocamldep"; "pa_optcomp"] ["syntax/pa_optcomp.cmo"];
+
              (* Add directories for compiler-libraries: *)
              let paths = List.filter Sys.file_exists [path; path / "typing"; path / "parsing"; path / "utils"] in
              let paths = List.map (fun path -> S [A "-I"; A path]) paths in
diff --git a/src/lib/uTop.ml b/src/lib/uTop.ml
index a4afe55..bfa45c2 100644
--- a/src/lib/uTop.ml
+++ b/src/lib/uTop.ml
@@ -600,11 +600,13 @@ let () =
 
 let topfind_log, set_topfind_log = S.create ~eq:(fun _ _ -> false) []
 
+#if findlib_version >= (1, 4)
 let () =
   let real_log = !Topfind.log in
   Topfind.log := fun str ->
     set_topfind_log (str :: S.value topfind_log);
     if S.value topfind_verbose then real_log str
+#endif
 
 let () =
   Hashtbl.add
diff --git a/src/lib/uTop.mli b/src/lib/uTop.mli
index 72fcab8..07f332c 100644
--- a/src/lib/uTop.mli
+++ b/src/lib/uTop.mli
@@ -48,7 +48,8 @@ val set_hide_reserved : bool -> unit
   (** Modifies {!hide_reserved}. *)
 
 val topfind_verbose : bool signal
-  (** If [false] (the default) messages from findlib are hidden. *)
+  (** If [false] (the default) messages from findlib are hidden. This is only effective
+      with findlib >= 1.4. *)
 
 val get_topfind_verbose : unit -> bool
   (** Returns the value of {!topfind_verbose}. *)
@@ -57,7 +58,8 @@ val set_topfind_verbose : bool -> unit
   (** Modifies {!topfind_verbose}. *)
 
 val topfind_log : string list signal
-  (** List of messages logged by findlib since the beginning of the session. *)
+  (** List of messages logged by findlib since the beginning of the session. This
+      requires findlib >= 1.4. *)
 
 val show_box : bool signal
   (** If [true] (the default) the completion bar is displayed. *)