diff --git a/CHANGES.md b/CHANGES.md
index 0881bc1..ed9789f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,8 @@
 * Remove deprecated values `prompt_continue`, `prompt_comment`, `smart_accept`,
   `new_prompt_hooks`, `at_new_prompt` (#..., @emillon)
 
+* Require OCaml 4.11.0 or newer. (#444, @emillon)
+
 2.12.1 (2023-04-21)
 -------------------
 
diff --git a/dune-project b/dune-project
index 51d781b..3bca72e 100644
--- a/dune-project
+++ b/dune-project
@@ -15,7 +15,7 @@
  (description
   "utop is an improved toplevel (i.e., Read-Eval-Print Loop or REPL) for OCaml. It can run in a terminal or in Emacs. It supports line edition, history, real-time and context sensitive completion, colors, and more. It integrates with the Tuareg mode in Emacs.")
  (depends
-  (ocaml (>= 4.08.0))
+  (ocaml (>= 4.11.0))
   base-unix
   base-threads
   (ocamlfind (>= 1.7.2))
diff --git a/src/lib/uTop.ml b/src/lib/uTop.ml
index 571b491..8502976 100644
--- a/src/lib/uTop.ml
+++ b/src/lib/uTop.ml
@@ -359,13 +359,7 @@ let check_phrase phrase =
             (fun () ->
                Str.eval
                  (Exp.fun_ Nolabel None (Pat.construct unit None)
-                   (Exp.letmodule (with_loc loc
-                        #if OCAML_VERSION >= (4, 10, 0)
-                        (Some "_")
-                        #else
-                          "_"
-                        #endif
-                        )
+                   (Exp.letmodule (with_loc loc (Some "_"))
                       (Mod.structure (item :: items))
                       (Exp.construct unit None))))
         in
diff --git a/src/lib/uTop_compat.ml b/src/lib/uTop_compat.ml
index ca6430e..23c66a9 100644
--- a/src/lib/uTop_compat.ml
+++ b/src/lib/uTop_compat.ml
@@ -1,10 +1,3 @@
-let lookup_value =
-#if OCAML_VERSION >= (4, 10, 0)
-  Env.find_value_by_name
-#else
-  Env.lookup_value
-#endif
-
 let get_desc x =
 #if OCAML_VERSION >= (4, 14, 0)
   Types.get_desc x
@@ -19,51 +12,6 @@ let toploop_get_directive name =
   try Some (Hashtbl.find Toploop.directive_table name) with Not_found -> None
 #endif
 
-let lookup_module name env =
-#if OCAML_VERSION >= (4, 10, 0)
-  let path, md = Env.find_module_by_name name env in
-#else
-  let path = Env.lookup_module name env ~load:true in
-  let md = Env.find_module path env in
-#endif
-  (path, md.md_type)
-
-let lookup_label =
-#if OCAML_VERSION >= (4, 10, 0)
-  Env.find_label_by_name
-#else
-  Env.lookup_label
-#endif
-
-let lookup_modtype =
-#if OCAML_VERSION >= (4, 10, 0)
-  Env.find_modtype_by_name
-#else
-  Env.lookup_modtype
-#endif
-
-let lookup_constructor =
-#if OCAML_VERSION >= (4, 10, 0)
-  Env.find_constructor_by_name
-#else
-  Env.lookup_constructor
-#endif
-
-let lookup_class=
-#if OCAML_VERSION >= (4, 10, 0)
-  Env.find_class_by_name
-#else
-  Env.lookup_class
-#endif
-
-let longident_parse str =
-#if OCAML_VERSION >= (4, 11, 0)
-  let lexbuf = Lexing.from_string str in
-  Parse.longident lexbuf
-#else
-  Longident.parse str
-#endif
-
 let toploop_all_directive_names () =
 #if OCAML_VERSION >= (4, 13, 0)
   Toploop.all_directive_names ()
@@ -71,15 +19,6 @@ let toploop_all_directive_names () =
   Hashtbl.fold (fun dir _ acc -> dir::acc) Toploop.directive_table []
 #endif
 
-#if OCAML_VERSION >= (4, 10, 0)
-let lookup_type longident env =
-  Env.find_type_by_name longident env
-#else
-let lookup_type longident env =
-  let path = Env.lookup_type longident env in
-  (path, Env.find_type path env)
-#endif
-
 let set_load_path path =
 #if OCAML_VERSION >= (5, 0, 0)
   Load_path.init path ~auto_include:Load_path.no_auto_include
@@ -94,13 +33,6 @@ let toploop_use_silently fmt name =
   Toploop.use_silently fmt name
 #endif
 
-module Persistent_signature =
-#if OCAML_VERSION >= (4, 09, 0)
-  Persistent_env.Persistent_signature
-#else
-  Env.Persistent_signature
-#endif
-
 let toploop_set_paths () =
 #if OCAML_VERSION >= (5, 0, 0)
   Toploop.set_paths ~auto_include:Load_path.no_auto_include ()
@@ -115,22 +47,6 @@ let toploop_load_file ppf fn =
   Topdirs.load_file ppf fn
 #endif
 
-let iter_structure expr =
-#if OCAML_VERSION >= (4,09,0)
-  let next iterator e = Tast_iterator.default_iterator.expr iterator e in
-  let expr iterator = expr (next iterator) in
-  let iter = { Tast_iterator.default_iterator with expr } in
-  iter.structure iter
-#else
-  let module Search =
-    TypedtreeIter.MakeIterator(struct
-      include TypedtreeIter.DefaultIteratorArgument
-
-      let enter_expression = expr ignore
-     end) in
-  Search.iter_structure
-#endif
-
 (** Returns whether the given path is persistent. *)
 let rec is_persistent_path = function
   | Path.Pident id -> Ident.persistent id
diff --git a/src/lib/uTop_complete.ml b/src/lib/uTop_complete.ml
index bfb6759..4a5794a 100644
--- a/src/lib/uTop_complete.ml
+++ b/src/lib/uTop_complete.ml
@@ -494,9 +494,9 @@ let names_of_module longident =
   try
     Longident_map.find longident !local_names_by_longident
   with Not_found ->
-    match lookup_env lookup_module longident !Toploop.toplevel_env with
-      | Some(path, module_type) ->
-          let names = names_of_module_type module_type in
+    match lookup_env Env.find_module_by_name longident !Toploop.toplevel_env with
+      | Some(path, {md_type; _}) ->
+          let names = names_of_module_type md_type in
           local_names_by_path := Path_map.add path names !local_names_by_path;
           local_names_by_longident := Longident_map.add longident names !local_names_by_longident;
           names
@@ -508,9 +508,9 @@ let fields_of_module longident =
   try
     Longident_map.find longident !local_fields_by_longident
   with Not_found ->
-    match lookup_env lookup_module longident !Toploop.toplevel_env with
-      | Some(path, module_type) ->
-          let fields = fields_of_module_type module_type in
+    match lookup_env Env.find_module_by_name longident !Toploop.toplevel_env with
+      | Some(path, {md_type; _}) ->
+          let fields = fields_of_module_type md_type in
           local_fields_by_path := Path_map.add path fields !local_fields_by_path;
           local_fields_by_longident := Longident_map.add longident fields !local_fields_by_longident;
           fields
@@ -521,10 +521,8 @@ let fields_of_module longident =
 let list_global_names () =
   let rec loop acc = function
     | Env.Env_empty -> acc
-#if OCAML_VERSION >= (4, 10, 0)
     | Env.Env_value_unbound _-> acc
     | Env.Env_module_unbound _-> acc
-#endif
     | Env.Env_value(summary, id, _) ->
         loop (add (Ident.name id) acc) summary
     | Env.Env_type(summary, id, decl) ->
@@ -545,13 +543,8 @@ let list_global_names () =
         loop (add (Ident.name id) acc) summary
     | Env.Env_constraints (summary, _) ->
         loop acc summary
-#if OCAML_VERSION >= (4, 10, 0)
     | Env.Env_copy_types summary ->
         loop acc summary
-#else
-    | Env.Env_copy_types (summary, _) ->
-        loop acc summary
-#endif
     | Env.Env_open(summary, path) ->
         match try Some (Path_map.find path !local_names_by_path) with Not_found -> None with
           | Some names ->
@@ -582,10 +575,8 @@ let replace x y set =
 let list_global_fields () =
   let rec loop acc = function
     | Env.Env_empty -> acc
-#if OCAML_VERSION >= (4, 10, 0)
     | Env.Env_value_unbound _-> acc
     | Env.Env_module_unbound _-> acc
-#endif
     | Env.Env_value(summary, id, _) ->
         loop (add (Ident.name id) acc) summary
     | Env.Env_type(summary, id, decl) ->
@@ -606,13 +597,8 @@ let list_global_fields () =
         loop (add (Ident.name id) acc) summary
     | Env.Env_constraints (summary, _) ->
         loop acc summary
-#if OCAML_VERSION >= (4, 10, 0)
     | Env.Env_copy_types summary ->
         loop acc summary
-#else
-    | Env.Env_copy_types (summary, _) ->
-        loop acc summary
-#endif
     | Env.Env_open(summary, path) ->
         match try Some (Path_map.find path !local_fields_by_path) with Not_found -> None with
           | Some fields ->
@@ -695,7 +681,7 @@ let rec find_object meths type_expr =
               None
 
 let methods_of_object longident meths =
-  match lookup_env lookup_value longident !Toploop.toplevel_env with
+  match lookup_env Env.find_value_by_name longident !Toploop.toplevel_env with
     | None ->
         []
     | Some (path, { val_type = type_expr }) ->
@@ -735,7 +721,7 @@ let rec labels_of_type acc type_expr =
         String_map.bindings acc
 
 let labels_of_function longident meths =
-  match lookup_env lookup_value longident !Toploop.toplevel_env with
+  match lookup_env Env.find_value_by_name longident !Toploop.toplevel_env with
     | None ->
         []
     | Some (path, { val_type = type_expr }) ->
@@ -746,7 +732,7 @@ let labels_of_function longident meths =
               labels_of_type String_map.empty type_expr
 
 let labels_of_newclass longident =
-  match lookup_env lookup_class longident !Toploop.toplevel_env with
+  match lookup_env Env.find_class_by_name longident !Toploop.toplevel_env with
     | None ->
         []
     | Some (path, { cty_new = None }) ->
@@ -830,7 +816,7 @@ let complete ~phrase_terminator ~input =
 
     | [(Symbol "#", _); (Lident "typeof", _); (String (tlen, false), loc)] ->
       let prefix = String.sub input (loc.ofs1 + tlen) (String.length input - loc.ofs1 - tlen) in
-      begin match longident_parse prefix with
+      begin match Parse.longident (Lexing.from_string prefix) with
       | Longident.Ldot (lident, last_prefix) ->
         let set = names_of_module lident in
         let compls = lookup last_prefix (String_set.elements set) in
diff --git a/src/lib/uTop_main.ml b/src/lib/uTop_main.ml
index 6447e08..e786f54 100644
--- a/src/lib/uTop_main.ml
+++ b/src/lib/uTop_main.ml
@@ -333,19 +333,15 @@ end = struct
     | Mty_signature s -> walk_sig pp ~path s
     | _ -> ()
 
-  let find_module id env =
-    let name = Longident.Lident (Ident.name id) in
-    lookup_module name env
-
   let scan_cmis =
     let new_cmis = ref [] in
-    let default_load = !Persistent_signature.load in
+    let default_load = !Persistent_env.Persistent_signature.load in
     let load ~unit_name =
       let res = default_load ~unit_name in
       (match res with None -> () | Some x -> new_cmis := x.cmi :: !new_cmis);
       res
     in
-    Persistent_signature.load := load;
+    Persistent_env.Persistent_signature.load := load;
 
     fun pp ->
       List.iter (fun (cmi : Cmi_format.cmi_infos) ->
@@ -359,9 +355,10 @@ end = struct
     fun pp ->
       let env = !Toploop.toplevel_env in
       let scan_module env id =
-        let path, md = find_module id env in
+        let name = Longident.Lident (Ident.name id) in
+        let path, {md_type; _} = Env.find_module_by_name name env in
         if path = Path.Pident id then
-          walk_mty pp (Longident.Lident (Ident.name id)) md
+          walk_mty pp name md_type
       in
       let rec scan_globals last = function
         | [] -> ()
@@ -376,15 +373,9 @@ end = struct
         | Env.Env_module (s, id, _, _) ->
           scan_summary last s;
           scan_module env id
-#if OCAML_VERSION >= (4, 10, 0)
         | Env.Env_copy_types s
-#else
-        | Env.Env_copy_types (s, _)
-#endif
-#if OCAML_VERSION >= (4, 10, 0)
         | Env.Env_value_unbound (s, _, _)
         | Env.Env_module_unbound (s, _, _)
-#endif
         | Env.Env_persistent (s, _)
         | Env.Env_value (s, _, _)
         | Env.Env_type (s, _, _)
@@ -590,7 +581,7 @@ let rule_path rule =
     try
       let env = !Toploop.toplevel_env in
       let path =
-        match lookup_type rule.type_to_rewrite env with
+        match Env.find_type_by_name rule.type_to_rewrite env with
         | path, { Types.type_kind     = Types.Type_abstract
                 ; Types.type_private  = Asttypes.Public
                 ; Types.type_manifest = Some ty
@@ -611,7 +602,7 @@ let rule_path rule =
    and is persistent. *)
 let is_persistent_in_env longident =
   try
-    is_persistent_path (fst (lookup_value longident !Toploop.toplevel_env))
+    is_persistent_path (fst (Env.find_value_by_name longident !Toploop.toplevel_env))
   with Not_found ->
     false
 
@@ -1182,7 +1173,7 @@ end
    +-----------------------------------------------------------------+ *)
 
 let typeof sid =
-  let id  = longident_parse sid in
+  let id = Parse.longident (Lexing.from_string sid) in
   let env = !Toploop.toplevel_env in
   let from_type_desc = function
     | Types.Tconstr (path, _, _) ->
@@ -1192,33 +1183,33 @@ let typeof sid =
   in
   let out_sig_item =
     try
-      let (path, ty_decl) = lookup_type id env in
+      let (path, ty_decl) = Env.find_type_by_name id env in
       let id = Ident.create_local (Path.name path) in
       Some (Printtyp.tree_of_type_declaration id ty_decl Types.Trec_not)
     with Not_found ->
     try
-      let (path, val_descr) = lookup_value id env in
+      let (path, val_descr) = Env.find_value_by_name id env in
       let id = Ident.create_local (Path.name path) in
       Some (Printtyp.tree_of_value_description id val_descr)
     with Not_found ->
     try
-      let lbl_desc = lookup_label id env in
+      let lbl_desc = Env.find_label_by_name id env in
       let (path, ty_decl) = from_type_desc (get_desc lbl_desc.Types.lbl_res) in
       let id = Ident.create_local (Path.name path) in
       Some (Printtyp.tree_of_type_declaration id ty_decl Types.Trec_not)
     with Not_found ->
     try
-      let path, mod_typ = lookup_module id env in
+      let path, {Types.md_type; _} = Env.find_module_by_name id env in
       let id = Ident.create_local (Path.name path) in
-      Some (Printtyp.tree_of_module id mod_typ Types.Trec_not)
+      Some (Printtyp.tree_of_module id md_type Types.Trec_not)
     with Not_found ->
     try
-      let (path, mty_decl) = lookup_modtype id env in
+      let (path, mty_decl) = Env.find_modtype_by_name id env in
       let id = Ident.create_local (Path.name path) in
       Some (Printtyp.tree_of_modtype_declaration id mty_decl)
     with Not_found ->
     try
-      let cstr_desc = lookup_constructor id env in
+      let cstr_desc = Env.find_constructor_by_name id env in
       match cstr_desc.Types.cstr_tag with
       | _ ->
         let (path, ty_decl) = from_type_desc (get_desc cstr_desc.Types.cstr_res) in
@@ -1276,7 +1267,6 @@ let prepare () =
       Format.eprintf "Uncaught exception: %s\n" (Printexc.to_string exn);
       false
 
-#if OCAML_VERSION >= (4, 09, 0)
 external caml_sys_modify_argv : string array -> unit =
   "caml_sys_modify_argv"
 let override_argv () =
@@ -1284,14 +1274,6 @@ let override_argv () =
   let copy = Array.init len (fun i -> Sys.argv.(i+ !Arg.current)) in
   caml_sys_modify_argv copy;
   Arg.current := 0
-#else
-let override_argv () =
-  let len = Array.length Sys.argv - !Arg.current in
-  Array.blit Sys.argv !Arg.current Sys.argv 0 len;
-  Obj.truncate (Obj.repr Sys.argv) len;
-  Arg.current := 0
-#endif
-
 
 let run_script name =
   (* To prevent message from camlp4 *)
@@ -1552,6 +1534,12 @@ let walk dir ~init ~f =
   | exception Unix.Unix_error(ENOENT, _, _) -> init
   | _ -> loop dir init
 
+let iter_structure expr =
+  let next iterator e = Tast_iterator.default_iterator.expr iterator e in
+  let expr iterator = expr (next iterator) in
+  let iter = { Tast_iterator.default_iterator with expr } in
+  iter.structure iter
+
 let interact ?(search_path=[]) ?(build_dir="_build") ~unit ~loc:(fname, lnum, cnum, _)
       ~values =
   let search_path = walk build_dir ~init:search_path ~f:(fun dir acc -> dir :: acc) in
diff --git a/utop.opam b/utop.opam
index ad8b4b3..d609715 100644
--- a/utop.opam
+++ b/utop.opam
@@ -11,7 +11,7 @@ doc: "https://ocaml-community.github.io/utop/"
 bug-reports: "https://github.com/ocaml-community/utop/issues"
 depends: [
   "dune" {>= "2.0"}
-  "ocaml" {>= "4.08.0"}
+  "ocaml" {>= "4.11.0"}
   "base-unix"
   "base-threads"
   "ocamlfind" {>= "1.7.2"}