diff --git a/benchs/dune b/benchs/dune
index 5c65db84..21ff71ef 100644
--- a/benchs/dune
+++ b/benchs/dune
@@ -2,7 +2,7 @@
  (names run_benchs run_bench_hash run_objsize)
  (libraries containers containers-data containers-thread benchmark gen iter
    qcheck oseq batteries base sek)
- (flags :standard -warn-error -3-5 -safe-string -color always -open CCShims_)
+ (flags :standard -warn-error -3-5 -safe-string -color always)
  (optional)
  (ocamlopt_flags :standard -O3 -color always -unbox-closures
    -unbox-closures-factor 20))
diff --git a/src/cbor/containers_cbor.ml b/src/cbor/containers_cbor.ml
index 62f0e003..65da19c0 100644
--- a/src/cbor/containers_cbor.ml
+++ b/src/cbor/containers_cbor.ml
@@ -44,9 +44,6 @@ let rec pp_diagnostic out (self : t) =
 let to_string_diagnostic (self : t) : string =
   Format.asprintf "@[<h>%a@]" pp_diagnostic self
 
-(* we use funtions from Bytes *)
-[@@@ifge 4.08]
-
 exception Indefinite
 
 let[@inline] i64_to_int i =
@@ -323,5 +320,3 @@ let encode ?(buf = Buffer.create 32) (self : t) : string =
   in
   encode_val self;
   Buffer.contents buf
-
-[@@@endif]
diff --git a/src/cbor/containers_cbor.mli b/src/cbor/containers_cbor.mli
index fe3537f7..4ca08772 100644
--- a/src/cbor/containers_cbor.mli
+++ b/src/cbor/containers_cbor.mli
@@ -5,9 +5,6 @@
 
   {b note} this is experimental.
 
-  {b note} this is only available on OCaml >= 4.08. Below that, the module
-    is empty.
-
   @since 3.9
   *)
 
@@ -26,15 +23,9 @@ type t =
 
 val pp_diagnostic : t CCFormat.printer
 val to_string_diagnostic : t -> string
-
-(* we use funtions from Bytes *)
-[@@@ifge 4.08]
-
 val encode : ?buf:Buffer.t -> t -> string
 val decode : string -> (t, string) result
 
 val decode_exn : string -> t
 (** Like {!decode}.
     @raise Failure if the string isn't valid *)
-
-[@@@endif]
diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index f9d7c2a8..00c57142 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -11,30 +11,8 @@ type 'a printer = Format.formatter -> 'a -> unit
 
 (** {2 Arrays} *)
 
-open CCShims_
-
-[@@@ifge 4.8]
-
 include Array
 
-[@@@elifge 4.6]
-
-include Array
-
-type 'a t = 'a array
-
-[@@@else_]
-
-include Array
-
-module Floatarray = struct
-  type t = float array
-end
-
-type 'a t = 'a array
-
-[@@@endif]
-
 let empty = [||]
 
 let get_safe a i =
@@ -619,16 +597,12 @@ module Infix = struct
   let ( -- ) = ( -- )
   let ( --^ ) = ( --^ )
 
-  [@@@ifge 4.8]
-
   type 'a t = 'a array
 
   let ( let* ) = ( >>= )
   let ( let+ ) = ( >|= )
   let[@inline] ( and+ ) a1 a2 = monoid_product (fun x y -> x, y) a1 a2
   let ( and* ) = ( and+ )
-
-  [@@@endif]
 end
 
 include Infix
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index 4ec5b1a9..d19d4252 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -14,31 +14,9 @@ type 'a printer = Format.formatter -> 'a -> unit
 
 (** {2 Arrays} *)
 
-[@@@ifge 4.8]
-
 include module type of Array
 (** @inline *)
 
-[@@@elifge 4.6]
-
-include module type of Array
-(** @inline *)
-
-type 'a t = 'a array
-
-[@@@else_]
-
-include module type of Array
-(** @inline *)
-
-module Floatarray : sig
-  type t = float array
-end
-
-type 'a t = 'a array
-
-[@@@endif]
-
 val empty : 'a t
 (** [empty] is the empty array, physically equal to [[||]]. *)
 
@@ -152,7 +130,6 @@ val max_exn : ('a -> 'a -> int) -> 'a t -> 'a
     @raise Invalid_argument if [a] is empty.
     @since 3.12 *)
 
-
 val argmax : ('a -> 'a -> int) -> 'a t -> int option
 (** [argmax cmp a] returns [None] if [a] is empty, otherwise, returns [Some i] where [i]
     is the index of a maximum element in [a] with respect to [cmp].
@@ -375,14 +352,10 @@ module Infix : sig
   (** [x --^ y] creates an array containing integers in the range [x .. y]. Right bound excluded.
       @since 0.17 *)
 
-  [@@@ifge 4.8]
-
-  include CCShims_syntax.LET with type 'a t := 'a array
-  (** Let operators on OCaml >= 4.08.0, nothing otherwise
-      @since 2.8
-      @inline *)
-
-  [@@@endif]
+  val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+  val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+  val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+  val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
 end
 
 include module type of Infix
diff --git a/src/core/CCArrayLabels.mli b/src/core/CCArrayLabels.mli
index 6da09570..8663c7dd 100644
--- a/src/core/CCArrayLabels.mli
+++ b/src/core/CCArrayLabels.mli
@@ -14,29 +14,9 @@ type 'a printer = Format.formatter -> 'a -> unit
 
 (** {2 Arrays} *)
 
-[@@@ifge 4.8]
-
 include module type of ArrayLabels with module Floatarray = Array.Floatarray
 (** @inline *)
 
-[@@@elifge 4.6]
-
-include module type of ArrayLabels with module Floatarray = Array.Floatarray
-(** @inline *)
-
-type 'a t = 'a array
-
-[@@@else_]
-
-include module type of ArrayLabels
-(** @inline *)
-
-module Floatarray = CCArray.Floatarray
-
-type 'a t = 'a array
-
-[@@@endif]
-
 val empty : 'a t
 (** [empty] is the empty array, physically equal to [[||]]. *)
 
@@ -151,7 +131,6 @@ val max_exn : cmp:('a -> 'a -> int) -> 'a t -> 'a
     @raise Invalid_argument if [a] is empty.
     @since 3.12 *)
 
-
 val argmax : cmp:('a -> 'a -> int) -> 'a t -> int option
 (** [argmax ~cmp a] returns [None] if [a] is empty, otherwise, returns [Some i] where [i]
     is the index of a maximum element in [a] with respect to [cmp].
@@ -389,14 +368,10 @@ module Infix : sig
   (** [x --^ y] creates an array containing integers in the range [x .. y]. Right bound excluded.
       @since 0.17 *)
 
-  [@@@ifge 4.8]
-
-  include CCShims_syntax.LET with type 'a t := 'a array
-  (** Let operators on OCaml >= 4.08.0, nothing otherwise
-      @since 2.8
-      @inline *)
-
-  [@@@endif]
+  val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+  val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+  val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+  val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
 end
 
 include module type of Infix
diff --git a/src/core/CCAtomic.ml b/src/core/CCAtomic.ml
index 3c60ba34..e617d06f 100644
--- a/src/core/CCAtomic.ml
+++ b/src/core/CCAtomic.ml
@@ -4,7 +4,7 @@ include Atomic
 
 [@@@else_]
 
-open CCShims_.Stdlib (* for == *)
+open Stdlib (* for == *)
 
 type 'a t = { mutable x: 'a }
 
diff --git a/src/core/CCBool.ml b/src/core/CCBool.ml
index 31120d9d..9166bd7b 100644
--- a/src/core/CCBool.ml
+++ b/src/core/CCBool.ml
@@ -1,6 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-open CCShims_
+
 
 type t = bool
 
diff --git a/src/core/CCCanonical_sexp.ml b/src/core/CCCanonical_sexp.ml
index 8ce2d98d..41e5c511 100644
--- a/src/core/CCCanonical_sexp.ml
+++ b/src/core/CCCanonical_sexp.ml
@@ -2,7 +2,7 @@
 
 (** {1 Simple S-expression parsing/printing} *)
 
-open CCShims_
+
 
 type 'a or_error = ('a, string) result
 type 'a gen = unit -> 'a option
diff --git a/src/core/CCChar.ml b/src/core/CCChar.ml
index b9fca676..5936830a 100644
--- a/src/core/CCChar.ml
+++ b/src/core/CCChar.ml
@@ -14,12 +14,12 @@ let to_int = Char.code
 let to_string c = String.make 1 c
 
 module Infix = struct
-  let ( = ) : t -> t -> bool = CCShims_.Stdlib.( = )
-  let ( <> ) : t -> t -> bool = CCShims_.Stdlib.( <> )
-  let ( < ) : t -> t -> bool = CCShims_.Stdlib.( < )
-  let ( > ) : t -> t -> bool = CCShims_.Stdlib.( > )
-  let ( <= ) : t -> t -> bool = CCShims_.Stdlib.( <= )
-  let ( >= ) : t -> t -> bool = CCShims_.Stdlib.( >= )
+  let ( = ) : t -> t -> bool = Stdlib.( = )
+  let ( <> ) : t -> t -> bool = Stdlib.( <> )
+  let ( < ) : t -> t -> bool = Stdlib.( < )
+  let ( > ) : t -> t -> bool = Stdlib.( > )
+  let ( <= ) : t -> t -> bool = Stdlib.( <= )
+  let ( >= ) : t -> t -> bool = Stdlib.( >= )
 end
 
 include Infix
diff --git a/src/core/CCEqual.ml b/src/core/CCEqual.ml
index 37b74f70..62d05c44 100644
--- a/src/core/CCEqual.ml
+++ b/src/core/CCEqual.ml
@@ -2,7 +2,7 @@
 
 (** {1 Equality Combinators} *)
 
-open CCShims_
+
 
 type 'a t = 'a -> 'a -> bool
 
diff --git a/src/core/CCFloat.ml b/src/core/CCFloat.ml
index 13be50ad..f0a003de 100644
--- a/src/core/CCFloat.ml
+++ b/src/core/CCFloat.ml
@@ -1,6 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-open CCShims_
+
 
 type t = float
 
diff --git a/src/core/CCFloat.mli b/src/core/CCFloat.mli
index 8b142d74..7a4b68f8 100644
--- a/src/core/CCFloat.mli
+++ b/src/core/CCFloat.mli
@@ -3,7 +3,7 @@
 (** Basic operations on floating-point numbers
     @since 0.6.1 *)
 
-open CCShims_
+
 
 type t = float
 
diff --git a/src/core/CCFormat.ml b/src/core/CCFormat.ml
index 6c047cec..bb382423 100644
--- a/src/core/CCFormat.ml
+++ b/src/core/CCFormat.ml
@@ -301,8 +301,6 @@ let mark_close_style st : string =
   else
     ""
 
-[@@@ifge 4.8]
-
 type stag += Style of ANSI_codes.style list
 
 let pp_open_tag out s = pp_open_stag out (String_tag s)
@@ -359,41 +357,6 @@ let set_color_tag_handling ppf =
   in
   pp_set_formatter_stag_functions ppf funs'
 
-[@@@else_]
-
-(* either prints the tag of [s] or delegate to [or_else] *)
-let mark_open_tag st ~or_else (s : string) : string =
-  let open ANSI_codes in
-  try
-    let style = style_of_tag_ s in
-    mark_open_style st style
-  with No_such_style -> or_else s
-
-let mark_close_tag st ~or_else (s : string) : string =
-  let open ANSI_codes in
-  (* check if it's indeed about color *)
-  match style_of_tag_ s with
-  | _ -> mark_close_style st
-  | exception No_such_style -> or_else s
-
-(* add color handling to formatter [ppf] *)
-let set_color_tag_handling ppf =
-  let st = Stack.create () in
-  (* stack of styles *)
-  pp_set_mark_tags ppf true;
-  (* enable tags *)
-  let funs = pp_get_formatter_tag_functions ppf () in
-  let functions =
-    {
-      funs with
-      mark_open_tag = mark_open_tag st ~or_else:funs.mark_open_tag;
-      mark_close_tag = mark_close_tag st ~or_else:funs.mark_close_tag;
-    }
-  in
-  pp_set_formatter_tag_functions ppf functions
-
-[@@@endif]
-
 let set_color_default =
   let first = ref true in
   fun b ->
diff --git a/src/core/CCFormat.mli b/src/core/CCFormat.mli
index d762574f..bf894951 100644
--- a/src/core/CCFormat.mli
+++ b/src/core/CCFormat.mli
@@ -10,10 +10,10 @@ type 'a iter = ('a -> unit) -> unit
    see https://discuss.ocaml.org/t/extend-existing-module/1389/4
 *)
 
+(** @inline *)
 include module type of struct
   include Format
 end
-(** @inline *)
 
 type t = Format.formatter
 type -'a printer = t -> 'a -> unit
@@ -30,7 +30,6 @@ val int : int printer
 val string : string printer
 val bool : bool printer
 val float3 : float printer (* 3 digits after . *)
-
 val float : float printer
 
 val exn : exn printer
@@ -334,8 +333,6 @@ module ANSI_codes : sig
       is a very shiny style. *)
 end
 
-[@@@ifge 4.8]
-
 val styling : ANSI_codes.style list -> 'a printer -> 'a printer
 (** [styling st p] is the same printer as [p], except it locally sets
     the style [st].
@@ -363,8 +360,6 @@ val with_styling : ANSI_codes.style list -> t -> (unit -> 'a) -> 'a
     Available only on OCaml >= 4.08.
     @since 3.7 *)
 
-[@@@endif]
-
 (** {2 IO} *)
 
 val output : t -> 'a printer -> 'a -> unit
diff --git a/src/core/CCFun.ml b/src/core/CCFun.ml
index 4f2bf27d..141b26d0 100644
--- a/src/core/CCFun.ml
+++ b/src/core/CCFun.ml
@@ -11,34 +11,9 @@ let opaque_identity x = x
 (* import standard implementations, if any *)
 
 include Sys
-include CCShims_.Stdlib
-
-[@@@ifge 4.8]
-
+include Stdlib
 include Fun
 
-[@@@else_]
-[@@@ocaml.warning "-32"]
-
-external id : 'a -> 'a = "%identity"
-
-let[@inline] protect ~finally f =
-  try
-    let x = f () in
-    finally ();
-    x
-  with e ->
-    finally ();
-    raise e
-
-[@@@ocaml.warning "+32"]
-
-let[@inline] flip f x y = f y x
-let[@inline] const x _ = x
-let[@inline] negate f x = not (f x)
-
-[@@@endif]
-
 let compose f g x = g (f x)
 let compose_binop f g x y = g (f x) (f y)
 let curry f x y = f (x, y)
@@ -92,16 +67,11 @@ let rec iterate n f x =
 
 module Infix = struct
   (* default implem for some operators *)
-  let ( |> ) = CCShims_.Stdlib.( |> )
-  let ( @@ ) = CCShims_.Stdlib.( @@ )
+  let ( |> ) = Stdlib.( |> )
+  let ( @@ ) = Stdlib.( @@ )
   let ( %> ) = compose
   let[@inline] ( % ) f g x = f (g x)
-
-  [@@@ifge 4.8]
-
   let ( let@ ) = ( @@ )
-
-  [@@@endif]
 end
 
 include Infix
diff --git a/src/core/CCFun.mli b/src/core/CCFun.mli
index 4f4013db..a5cfeae5 100644
--- a/src/core/CCFun.mli
+++ b/src/core/CCFun.mli
@@ -2,27 +2,9 @@
 
 (** Basic operations on Functions *)
 
-[@@@ifge 4.8]
-
 include module type of Fun
 (** @inline *)
 
-[@@@else_]
-
-(* port from stdlib *)
-
-external id : 'a -> 'a = "%identity"
-(** This is an API imitating the new standard Fun module *)
-
-val flip : ('a -> 'b -> 'c) -> 'b -> 'a -> 'c
-val const : 'a -> _ -> 'a
-val negate : ('a -> bool) -> 'a -> bool
-val protect : finally:(unit -> unit) -> (unit -> 'a) -> 'a
-(* this doesn't have the exact same semantics as the stdlib's finally.
-    It will not attempt to catch exceptions raised from [finally] at all. *)
-
-[@@@endif]
-
 val compose : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c
 (** [compose f g x] is [g (f x)]. Composition. *)
 
@@ -102,14 +84,10 @@ module Infix : sig
   val ( % ) : ('b -> 'c) -> ('a -> 'b) -> 'a -> 'c
   (** [(f % g) x] or [(%) f g x] is [f (g x)]. Mathematical composition. *)
 
-  [@@@ifge 4.8]
-
   val ( let@ ) : ('a -> 'b) -> 'a -> 'b
   (** [let@ x = foo in bar] is the equivalent of [foo @@ fun x -> bar].
       It can be very useful for resource management, alongside with {!protect}.
       @since 3.11 *)
-
-  [@@@endif]
 end
 
 include module type of Infix
diff --git a/src/core/CCInt.ml b/src/core/CCInt.ml
index d391d0eb..52cf5d1d 100644
--- a/src/core/CCInt.ml
+++ b/src/core/CCInt.ml
@@ -1,17 +1,7 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-[@@@ifge 4.07]
-[@@@else_]
-
-module Stdlib = Pervasives
-
-[@@@endif]
-[@@@ifge 4.08]
-
 include Int
 
-[@@@endif]
-
 type t = int
 type 'a iter = ('a -> unit) -> unit
 
diff --git a/src/core/CCInt.mli b/src/core/CCInt.mli
index e09b1c4c..65b01ef1 100644
--- a/src/core/CCInt.mli
+++ b/src/core/CCInt.mli
@@ -2,13 +2,9 @@
 
 (** Basic Int functions *)
 
-[@@@ifge 4.08]
-
 include module type of Int
 (** @inline *)
 
-[@@@endif]
-
 type t = int
 
 val zero : t
diff --git a/src/core/CCInt32.ml b/src/core/CCInt32.ml
index dd78fc63..5a194685 100644
--- a/src/core/CCInt32.ml
+++ b/src/core/CCInt32.ml
@@ -1,6 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-open CCShims_
+
 include Int32
 
 let min : t -> t -> t = Stdlib.min
diff --git a/src/core/CCInt64.ml b/src/core/CCInt64.ml
index bfe8ec29..818dd277 100644
--- a/src/core/CCInt64.ml
+++ b/src/core/CCInt64.ml
@@ -1,6 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-open CCShims_
+
 include Int64
 
 let min : t -> t -> t = Stdlib.min
@@ -22,7 +22,7 @@ let hash_to_int64 (n : t) =
   logand !h max_int
 
 let[@inline] hash (n : t) : int =
-  to_int (hash_to_int64 n) land CCShims_.Stdlib.max_int
+  to_int (hash_to_int64 n) land Stdlib.max_int
 
 (* see {!CCInt.popcount} for more details *)
 let[@inline] popcount (b : t) : int =
diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index da0d3b67..79a57708 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -2,8 +2,6 @@
 
 (** {1 Complements to list} *)
 
-open CCShims_
-
 (* backport new functions from stdlib here *)
 
 [@@@ocaml.warning "-32"]
@@ -52,18 +50,8 @@ let rec assq_opt x = function
 
 (* end of backport *)
 
-[@@@ifge 4.8]
-
 include List
 
-[@@@else_]
-
-include List
-
-type +'a t = 'a list
-
-[@@@endif]
-
 let empty = []
 
 let is_empty = function
@@ -1473,16 +1461,11 @@ module Infix = struct
   let ( <$> ) = map
   let ( -- ) = ( -- )
   let ( --^ ) = ( --^ )
-
-  [@@@ifge 4.8]
-
   let ( let+ ) = ( >|= )
   let ( let* ) = ( >>= )
   let[@inline] ( and+ ) l1 l2 = product (fun x y -> x, y) l1 l2
   let ( and* ) = ( and+ )
   let ( and& ) = combine_shortest
-
-  [@@@endif]
 end
 
 include Infix
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index 7030fac4..b4f5078f 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -10,22 +10,11 @@ type 'a gen = unit -> 'a option
 type 'a printer = Format.formatter -> 'a -> unit
 type 'a random_gen = Random.State.t -> 'a
 
-[@@@ifge 4.8]
-
 include module type of List with type 'a t := 'a list
 (** @inline *)
 
 type +'a t = 'a list
 
-[@@@else_]
-
-include module type of List
-(** @inline *)
-
-type +'a t = 'a list
-
-[@@@endif]
-
 val empty : 'a t
 (** [empty] is [[]]. *)
 
@@ -936,10 +925,10 @@ module Infix : sig
   (** [i --^ j] is the infix alias for [range']. Second bound [j] excluded.
       @since 0.17 *)
 
-  [@@@ifge 4.08]
-
-  include CCShims_syntax.LET with type 'a t := 'a t
-  (** @inline *)
+  val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+  val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+  val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+  val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
 
   val ( and& ) : 'a list -> 'b list -> ('a * 'b) list
   (** [(and&)] is {!combine_shortest}.
@@ -957,8 +946,6 @@ module Infix : sig
     ]}
     @since 3.1
   *)
-
-  [@@@endif]
 end
 
 include module type of Infix
diff --git a/src/core/CCNativeint.ml b/src/core/CCNativeint.ml
index af81801d..fd284905 100644
--- a/src/core/CCNativeint.ml
+++ b/src/core/CCNativeint.ml
@@ -1,6 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-open CCShims_
+
 include Nativeint
 
 let min : t -> t -> t = Stdlib.min
diff --git a/src/core/CCOption.ml b/src/core/CCOption.ml
index e6276a50..10bd4239 100644
--- a/src/core/CCOption.ml
+++ b/src/core/CCOption.ml
@@ -181,9 +181,6 @@ module Infix = struct
   let ( <*> ) = ( <*> )
   let ( <$> ) = map
   let ( <+> ) = ( <+> )
-
-  [@@@ifge 4.8]
-
   let ( let+ ) = ( >|= )
   let ( let* ) = ( >>= )
 
@@ -193,8 +190,6 @@ module Infix = struct
     | _ -> None
 
   let ( and* ) = ( and+ )
-
-  [@@@endif]
 end
 
 include Infix
diff --git a/src/core/CCOption.mli b/src/core/CCOption.mli
index 24c0d4c5..06ad03d9 100644
--- a/src/core/CCOption.mli
+++ b/src/core/CCOption.mli
@@ -175,14 +175,10 @@ module Infix : sig
   val ( <+> ) : 'a t -> 'a t -> 'a t
   (** [o1 <+> o2] is [o1] if [o1] is [Some _], [o2] if [o1] is [None]. *)
 
-  [@@@ifge 4.08]
-
-  include CCShims_syntax.LET with type 'a t := 'a t
-  (** Let operators on OCaml >= 4.08.0, nothing otherwise
-      @since 2.8
-      @inline *)
-
-  [@@@endif]
+  val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+  val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+  val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+  val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
 end
 
 include module type of Infix
diff --git a/src/core/CCOrd.ml b/src/core/CCOrd.ml
index 0d84b840..8c8eff06 100644
--- a/src/core/CCOrd.ml
+++ b/src/core/CCOrd.ml
@@ -2,7 +2,7 @@
 
 (** {1 Comparisons} *)
 
-open CCShims_
+
 
 type 'a t = 'a -> 'a -> int
 (** Comparison (total ordering) between two elements, that returns an int *)
diff --git a/src/core/CCParse.ml b/src/core/CCParse.ml
index 8ed04556..6c865bb9 100644
--- a/src/core/CCParse.ml
+++ b/src/core/CCParse.ml
@@ -1,5 +1,3 @@
-open CCShims_
-
 module Memo_tbl = Hashtbl.Make (struct
   type t = int * int (* id of parser, position *)
 
@@ -246,15 +244,10 @@ module Infix = struct
   let ( <|> ) = or_
   let ( ||| ) = both
   let[@inline] ( <?> ) p msg = set_error_message msg p
-
-  [@@@ifge 4.8]
-
   let ( let+ ) = ( >|= )
   let ( let* ) = ( >>= )
   let ( and+ ) = both
   let ( and* ) = ( and+ )
-
-  [@@@endif]
 end
 
 include Infix
@@ -302,7 +295,7 @@ let recurse slice p : _ t =
       (fun st ~ok ~err ->
         (* make sure these states are related. all slices share the
            same reference as the initial state they derive from. *)
-        assert (CCShims_.Stdlib.(st.cs == slice.cs));
+        assert (Stdlib.(st.cs == slice.cs));
         p.run slice ~ok:(fun _st x -> ok st x) ~err);
   }
 
@@ -761,7 +754,7 @@ let set_current_slice sl : _ t =
   {
     run =
       (fun _st ~ok ~err:_ ->
-        assert (CCShims_.Stdlib.(_st.cs == sl.cs));
+        assert (Stdlib.(_st.cs == sl.cs));
         ok sl ())
       (* jump to slice *);
   }
diff --git a/src/core/CCParse.mli b/src/core/CCParse.mli
index cc98dd19..39087562 100644
--- a/src/core/CCParse.mli
+++ b/src/core/CCParse.mli
@@ -1,4 +1,3 @@
-
 (** Very Simple Parser Combinators
 
     These combinators can be used to write very simple parsers, for example
@@ -675,14 +674,10 @@ module Infix : sig
       [a ||| b] parses [a], then [b], then returns the pair of their results.
       @since 3.6 *)
 
-  [@@@ifge 4.08]
-
-  include CCShims_syntax.LET with type 'a t := 'a t
-  (** Let operators on OCaml >= 4.08.0, nothing otherwise
-      @since 2.8
-      @inline *)
-
-  [@@@endif]
+  val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+  val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+  val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+  val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
 end
 
 include module type of Infix
diff --git a/src/core/CCRandom.ml b/src/core/CCRandom.ml
index 5a6b5862..61f8087c 100644
--- a/src/core/CCRandom.ml
+++ b/src/core/CCRandom.ml
@@ -177,15 +177,9 @@ let fix ?(sub1 = []) ?(sub2 = []) ?(subn = []) ~base fuel st =
 
 let pure x _st = x
 let ( <*> ) f g st = f st (g st)
-
-[@@@ifge 4.8]
-
 let ( let+ ) = ( >|= )
 let ( let* ) = ( >>= )
 let[@inline] ( and+ ) a1 a2 st = a1 st, a2 st
 let ( and* ) = ( and+ )
-
-[@@@endif]
-
 let __default_state = Random.State.make_self_init ()
 let run ?(st = __default_state) g = g st
diff --git a/src/core/CCRandom.mli b/src/core/CCRandom.mli
index 2282bd20..af070cef 100644
--- a/src/core/CCRandom.mli
+++ b/src/core/CCRandom.mli
@@ -2,10 +2,10 @@
 
 (** Random Generators *)
 
+(** @inline *)
 include module type of struct
   include Random
 end
-(** @inline *)
 
 type state = Random.State.t
 
@@ -151,15 +151,10 @@ val fix :
 
 val pure : 'a -> 'a t
 val ( <*> ) : ('a -> 'b) t -> 'a t -> 'b t
-
-[@@@ifge 4.08]
-
-include CCShims_syntax.LET with type 'a t := 'a t
-(** Let operators on OCaml >= 4.08.0, nothing otherwise
-    @since 2.8
-    @inline *)
-
-[@@@endif]
+val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
 
 (** {4 Run a generator} *)
 
diff --git a/src/core/CCResult.ml b/src/core/CCResult.ml
index 1e36de21..27aae43c 100644
--- a/src/core/CCResult.ml
+++ b/src/core/CCResult.ml
@@ -263,9 +263,6 @@ module Infix = struct
   let ( >|= ) e f = map f e
   let ( >>= ) e f = flat_map f e
   let ( <*> ) = ( <*> )
-
-  [@@@ifge 4.8]
-
   let ( let+ ) = ( >|= )
   let ( let* ) = ( >>= )
 
@@ -276,8 +273,6 @@ module Infix = struct
     | _, Error e -> Error e
 
   let ( and* ) = ( and+ )
-
-  [@@@endif]
 end
 
 include Infix
diff --git a/src/core/CCResult.mli b/src/core/CCResult.mli
index 47f1be1b..74247a8e 100644
--- a/src/core/CCResult.mli
+++ b/src/core/CCResult.mli
@@ -186,8 +186,6 @@ module Infix : sig
       [Ok (a b)]. Otherwise, it fails, and the error of [a] is chosen
       over the error of [b] if both fail. *)
 
-  [@@@ifge 4.08]
-
   val ( let+ ) : ('a, 'e) t -> ('a -> 'b) -> ('b, 'e) t
   (** @since 2.8 *)
 
@@ -199,8 +197,6 @@ module Infix : sig
 
   val ( and* ) : ('a, 'e) t -> ('b, 'e) t -> ('a * 'b, 'e) t
   (** @since 2.8 *)
-
-  [@@@endif]
 end
 
 include module type of Infix
diff --git a/src/core/CCSeq.ml b/src/core/CCSeq.ml
index ba5bacb3..68c479d2 100644
--- a/src/core/CCSeq.ml
+++ b/src/core/CCSeq.ml
@@ -6,17 +6,8 @@ type 'a equal = 'a -> 'a -> bool
 type 'a ord = 'a -> 'a -> int
 type 'a printer = Format.formatter -> 'a -> unit
 
-[@@@ifge 4.07]
-
 include Seq
 
-[@@@else_]
-
-type +'a t = unit -> 'a node
-and +'a node = 'a Seq.node = Nil | Cons of 'a * 'a t
-
-[@@@endif]
-
 let nil () = Nil
 let cons a b () = Cons (a, b)
 let empty = nil
@@ -24,7 +15,10 @@ let singleton x () = Cons (x, nil)
 
 let init n f =
   let rec aux i () =
-    if i >= n then Nil else Cons (f i, aux (i+1))
+    if i >= n then
+      Nil
+    else
+      Cons (f i, aux (i + 1))
   in
   aux 0
 
@@ -101,8 +95,8 @@ let fold_left = fold
 let foldi f acc res =
   let rec aux acc i res =
     match res () with
-      | Nil -> acc
-      | Cons (s, cont) -> aux (f acc i s) (i+1) cont
+    | Nil -> acc
+    | Cons (s, cont) -> aux (f acc i s) (i + 1) cont
   in
   aux acc 0 res
 
@@ -193,7 +187,6 @@ let rec append l1 l2 () =
   | Cons (x, l1') -> Cons (x, append l1' l2)
 
 let rec cycle l () = append l (cycle l) ()
-
 let rec iterate f a () = Cons (a, iterate f (f a))
 
 let rec unfold f acc () =
@@ -213,23 +206,28 @@ let rec exists p l =
 
 let rec find p l =
   match l () with
-    | Nil -> None
-    | Cons (x, tl) ->
-      if p x then Some x else find p tl
+  | Nil -> None
+  | Cons (x, tl) ->
+    if p x then
+      Some x
+    else
+      find p tl
 
 let rec find_map f l =
   match l () with
-    | Nil -> None
-    | Cons (x, tl) ->
-      match f x with
-        | None -> find_map f tl
-        | e -> e
-
-let rec scan f acc res () = Cons (acc, fun () ->
-  match res () with
-  | Nil -> Nil
-  | Cons (s, cont) -> scan f (f acc s) cont ())
+  | Nil -> None
+  | Cons (x, tl) ->
+    (match f x with
+    | None -> find_map f tl
+    | e -> e)
 
+let rec scan f acc res () =
+  Cons
+    ( acc,
+      fun () ->
+        match res () with
+        | Nil -> Nil
+        | Cons (s, cont) -> scan f (f acc s) cont () )
 
 let rec flat_map f l () =
   match l () with
@@ -267,7 +265,6 @@ let product_with f l1 l2 =
   _next_left [] l1 [] l2
 
 let map_product = product_with
-
 let product l1 l2 = product_with (fun x y -> x, y) l1 l2
 
 let rec group eq l () =
@@ -297,7 +294,6 @@ let rec filter_map f l () =
     | Some y -> Cons (y, filter_map f l'))
 
 let flatten l = flat_map (fun x -> x) l
-
 let concat = flatten
 
 let range i j =
diff --git a/src/core/CCSeq.mli b/src/core/CCSeq.mli
index 37f000b5..26068b6f 100644
--- a/src/core/CCSeq.mli
+++ b/src/core/CCSeq.mli
@@ -13,18 +13,9 @@ type 'a printer = Format.formatter -> 'a -> unit
 
 (** {2 Basics} *)
 
-[@@@ifge 4.07]
-
 include module type of Seq
 (** @inline *)
 
-[@@@else_]
-
-type +'a t = unit -> 'a node
-and +'a node = 'a Seq.node = Nil | Cons of 'a * 'a t
-
-[@@@endif]
-
 val nil : 'a t
 val empty : 'a t
 val cons : 'a -> 'a t -> 'a t
@@ -173,13 +164,14 @@ val scan : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'a t
     @since 3.10 *)
 
 val flat_map : ('a -> 'b t) -> 'a t -> 'b t
+
 val concat_map : ('a -> 'b t) -> 'a t -> 'b t
 (** Alias of {!flat_map}
     @since 3.10 *)
 
 val filter_map : ('a -> 'b option) -> 'a t -> 'b t
-
 val flatten : 'a t t -> 'a t
+
 val concat : 'a t t -> 'a t
 (** Alias of {!flatten}.
     @since 3.10 *)
diff --git a/src/core/CCSexp.ml b/src/core/CCSexp.ml
index 9af0e888..7dcdf651 100644
--- a/src/core/CCSexp.ml
+++ b/src/core/CCSexp.ml
@@ -2,7 +2,7 @@
 
 (** {1 Simple S-expression parsing/printing} *)
 
-open CCShims_
+
 
 type 'a or_error = ('a, string) result
 type 'a gen = unit -> 'a option
diff --git a/src/core/CCSexp_lex.mll b/src/core/CCSexp_lex.mll
index 76e0ecca..b22844a1 100644
--- a/src/core/CCSexp_lex.mll
+++ b/src/core/CCSexp_lex.mll
@@ -1,5 +1,4 @@
 {
-  open CCShims_
   type token =
     | ATOM of string
     | LIST_OPEN
diff --git a/src/core/CCShims_.ml b/src/core/CCShims_.ml
deleted file mode 100644
index 7e4ca0f4..00000000
--- a/src/core/CCShims_.ml
+++ /dev/null
@@ -1,9 +0,0 @@
-[@@@ifge 4.07]
-
-module Stdlib = Stdlib
-
-[@@@else_]
-
-module Stdlib = Pervasives
-
-[@@@endif]
diff --git a/src/core/CCShims_syntax.mli b/src/core/CCShims_syntax.mli
deleted file mode 100644
index 95530a3f..00000000
--- a/src/core/CCShims_syntax.mli
+++ /dev/null
@@ -1,14 +0,0 @@
-[@@@ifge 4.8]
-
-(** Let operators on OCaml >= 4.08.0, nothing otherwise
-  @since 2.8 *)
-module type LET = sig
-  type 'a t
-
-  val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
-  val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
-  val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
-  val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
-end
-
-[@@@endif]
diff --git a/src/core/CCString.ml b/src/core/CCString.ml
index c41b7656..933c70b1 100644
--- a/src/core/CCString.ml
+++ b/src/core/CCString.ml
@@ -2,8 +2,6 @@
 
 (** {1 Basic String Utils} *)
 
-open CCShims_
-
 type 'a iter = ('a -> unit) -> unit
 type 'a gen = unit -> 'a option
 
@@ -388,14 +386,6 @@ module Split = struct
   let right ~by s = try Some (right_exn ~by s) with Not_found -> None
 end
 
-[@@@ifge 4.04]
-[@@@else_]
-
-let split_on_char c s : _ list =
-  Split.list_cpy ~drop:Split.no_drop ~by:(String.make 1 c) s
-
-[@@@endif]
-
 let split ~by s = Split.list_cpy ~by s
 
 let compare_versions a b =
@@ -979,10 +969,10 @@ let pp fmt s = Format.fprintf fmt "\"%s\"" s
 module Infix = struct
   let ( = ) = equal
   let ( <> ) a b = not (equal a b)
-  let ( > ) : t -> t -> bool = CCShims_.Stdlib.( > )
-  let ( >= ) : t -> t -> bool = CCShims_.Stdlib.( >= )
-  let ( < ) : t -> t -> bool = CCShims_.Stdlib.( < )
-  let ( <= ) : t -> t -> bool = CCShims_.Stdlib.( <= )
+  let ( > ) : t -> t -> bool = Stdlib.( > )
+  let ( >= ) : t -> t -> bool = Stdlib.( >= )
+  let ( < ) : t -> t -> bool = Stdlib.( < )
+  let ( <= ) : t -> t -> bool = Stdlib.( <= )
 end
 
 include Infix
diff --git a/src/core/CCUnit.ml b/src/core/CCUnit.ml
index 1e7cf14c..3fd9bf36 100644
--- a/src/core/CCUnit.ml
+++ b/src/core/CCUnit.ml
@@ -1,13 +1 @@
-[@@@ifge 4.08]
-
 include Unit
-
-[@@@else_]
-
-type t = unit
-
-let[@inline] equal (_ : t) (_ : t) = true
-let[@inline] compare (_ : t) (_ : t) = 0
-let to_string () = "()"
-
-[@@@endif]
diff --git a/src/core/CCUtf8_string.ml b/src/core/CCUtf8_string.ml
index 2d52a38b..ed148c37 100644
--- a/src/core/CCUtf8_string.ml
+++ b/src/core/CCUtf8_string.ml
@@ -4,7 +4,7 @@
 
     We only deal with UTF8 strings as they naturally map to OCaml bytestrings *)
 
-open CCShims_
+
 
 type uchar = Uchar.t
 type 'a gen = unit -> 'a option
diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 20d4053d..b577b7b2 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -671,11 +671,7 @@ let pp ?(pp_start = fun _ () -> ()) ?(pp_stop = fun _ () -> ())
     v;
   pp_stop fmt ()
 
-[@@@ifge 4.8]
-
 let ( let+ ) = ( >|= )
 let ( let* ) = ( >>= )
 let[@inline] ( and+ ) a1 a2 = monoid_product (fun x y -> x, y) a1 a2
 let ( and* ) = ( and+ )
-
-[@@@endif]
diff --git a/src/core/CCVector.mli b/src/core/CCVector.mli
index 0d639bff..7e858453 100644
--- a/src/core/CCVector.mli
+++ b/src/core/CCVector.mli
@@ -397,8 +397,6 @@ val pp :
     By defaults [pp_start] and [pp_stop] does nothing and [pp_sep] defaults to
     (fun out -> Format.fprintf out ",@ "). *)
 
-[@@@ifge 4.08]
-
 val ( let+ ) : ('a, 'e) t -> ('a -> 'b) -> ('b, 'e) t
 (** @since 2.8 *)
 
@@ -410,5 +408,3 @@ val ( let* ) : ('a, 'e) t -> ('a -> ('b, 'e) t) -> ('b, 'e) t
 
 val ( and* ) : ('a, 'e) t -> ('b, 'e) t -> ('a * 'b, 'e) t
 (** @since 2.8 *)
-
-[@@@endif]
diff --git a/src/core/containers.ml b/src/core/containers.ml
index 4518f939..be529eba 100644
--- a/src/core/containers.ml
+++ b/src/core/containers.ml
@@ -55,5 +55,5 @@ module Atomic = CCAtomic
 module Sexp = CCSexp
 module Sexp_intf = CCSexp_intf
 module Canonical_sexp = CCCanonical_sexp
-module Stdlib = CCShims_.Stdlib
+module Stdlib = Stdlib
 include Monomorphic
diff --git a/src/core/containersLabels.ml b/src/core/containersLabels.ml
index 7b4ae5a8..3add206c 100644
--- a/src/core/containersLabels.ml
+++ b/src/core/containersLabels.ml
@@ -52,5 +52,5 @@ module Monomorphic = CCMonomorphic
 module Utf8_string = CCUtf8_string
 module Sexp = CCSexp
 module Sexp_intf = CCSexp_intf
-module Stdlib = CCShims_.Stdlib
+module Stdlib = Stdlib
 include Monomorphic
diff --git a/src/core/dune b/src/core/dune
index 8e7c04d8..3d2c5c2a 100644
--- a/src/core/dune
+++ b/src/core/dune
@@ -2,7 +2,6 @@
  (name containers)
  (public_name containers)
  (wrapped false)
- (modules_without_implementation CCShims_syntax)
  (preprocess
   (action
    (run %{project_root}/src/core/cpp/cpp.exe %{input-file})))
diff --git a/src/core/tests/test_random.ml b/src/core/tests/test_random.ml
index d6bf8de0..54af6c32 100644
--- a/src/core/tests/test_random.ml
+++ b/src/core/tests/test_random.ml
@@ -24,7 +24,7 @@ let uniformity_test ?(size_hint = 10) k rng st =
   let confidence = 4. in
   let std = confidence *. sqrt (kf *. variance) in
   let predicate _key n acc =
-    let ( < ) (a : float) b = CCShims_.Stdlib.( < ) a b in
+    let ( < ) (a : float) b = Stdlib.( < ) a b in
     acc && abs_float (average -. float_of_int n) < std
   in
   Hashtbl.fold predicate histogram true
diff --git a/src/data/dune b/src/data/dune
index 853db29b..4bed1adf 100644
--- a/src/data/dune
+++ b/src/data/dune
@@ -3,5 +3,5 @@
  (public_name containers-data)
  (wrapped false)
  (flags :standard -warn-error -3 -w -70 -color always -safe-string
-   -strict-sequence -open CCShims_)
+   -strict-sequence)
  (libraries containers))
diff --git a/src/monomorphic/CCMonomorphic.ml b/src/monomorphic/CCMonomorphic.ml
index cb5873be..ce484654 100644
--- a/src/monomorphic/CCMonomorphic.ml
+++ b/src/monomorphic/CCMonomorphic.ml
@@ -1,12 +1,5 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-[@@@ifge 4.07]
-[@@@else_]
-
-module Stdlib = Pervasives
-
-[@@@endif]
-
 let ( = ) : int -> int -> bool = Stdlib.( = )
 let ( <> ) : int -> int -> bool = Stdlib.( <> )
 let ( < ) : int -> int -> bool = Stdlib.( < )
diff --git a/src/testlib/containers_testlib.ml b/src/testlib/containers_testlib.ml
index 63a7264f..0847c3f2 100644
--- a/src/testlib/containers_testlib.ml
+++ b/src/testlib/containers_testlib.ml
@@ -31,19 +31,9 @@ module Test = struct
     in
     Printf.sprintf "(test :file '%s'%s :n %d)" self.__FILE__ what self.n
 
-  [@@@ifge 4.08]
-
   let get_state (r : _ QCheck.TestResult.t) : _ QCheck.TestResult.state =
     QCheck.TestResult.get_state r
 
-  [@@@else_]
-
-  (* must have qcheck < 0.17 *)
-  let get_state (r : _ QCheck.TestResult.t) : _ QCheck.TestResult.state =
-    r.state
-
-  [@@@endif]
-
   let run ?(long = false) ~seed (self : t) : _ result =
     match
       let what = CCOption.map_or ~default:"" (fun s -> s ^ " ") self.name in
diff --git a/src/threads/CCPool.ml b/src/threads/CCPool.ml
index e438bd79..03678c1b 100644
--- a/src/threads/CCPool.ml
+++ b/src/threads/CCPool.ml
@@ -518,15 +518,10 @@ module Make (P : PARAM) = struct
       let ( >> ) a f = and_then a f
       let ( >|= ) a f = map f a
       let ( <*> ) = app
-
-      [@@@ifge 4.8]
-
       let ( let+ ) = ( >|= )
       let ( let* ) = ( >>= )
       let[@inline] ( and+ ) a1 a2 = monoid_product (fun x y -> x, y) a1 a2
       let ( and* ) = ( and+ )
-
-      [@@@endif]
     end
 
     include Infix
diff --git a/src/threads/CCPool.mli b/src/threads/CCPool.mli
index a27e7838..1987c011 100644
--- a/src/threads/CCPool.mli
+++ b/src/threads/CCPool.mli
@@ -148,14 +148,10 @@ module Make (P : PARAM) : sig
       val ( >> ) : 'a t -> (unit -> 'b t) -> 'b t
       val ( >|= ) : 'a t -> ('a -> 'b) -> 'b t
       val ( <*> ) : ('a -> 'b) t -> 'a t -> 'b t
-
-      [@@@ifge 4.08]
-
-      include CCShims_syntax.LET with type 'a t := 'a t
-      (** Let operators on OCaml >= 4.08.0, nothing otherwise
-          @since 2.8 *)
-
-      [@@@endif]
+      val ( let+ ) : 'a t -> ('a -> 'b) -> 'b t
+      val ( and+ ) : 'a t -> 'b t -> ('a * 'b) t
+      val ( let* ) : 'a t -> ('a -> 'b t) -> 'b t
+      val ( and* ) : 'a t -> 'b t -> ('a * 'b) t
     end
 
     include module type of Infix
diff --git a/src/threads/dune b/src/threads/dune
index e9f09e08..649a4a5f 100644
--- a/src/threads/dune
+++ b/src/threads/dune
@@ -3,7 +3,7 @@
  (public_name containers-thread)
  (wrapped false)
  (optional)
- (flags :standard -warn-error -a+8 -w -32 -safe-string -open CCShims_)
+ (flags :standard -warn-error -a+8 -w -32 -safe-string)
  (preprocess
   (action
    (run %{project_root}/src/core/cpp/cpp.exe %{input-file})))
diff --git a/tests/cbor/t_appendix_a.ml b/tests/cbor/t_appendix_a.ml
index aef954f5..a423b06f 100644
--- a/tests/cbor/t_appendix_a.ml
+++ b/tests/cbor/t_appendix_a.ml
@@ -1,7 +1,5 @@
 let verbose = try Sys.getenv "VERBOSE" = "1" with _ -> false
 
-[@@@ifge 4.08]
-
 module J = Yojson.Safe
 module Fmt = CCFormat
 module Cbor = Containers_cbor
@@ -174,5 +172,3 @@ let () =
   (*Format.printf "tests: %a@." (Fmt.Dump.list Test.pp) tests;*)
   run_tests tests;
   ()
-
-[@@@endif]
diff --git a/tests/core/t_cbor.ml b/tests/core/t_cbor.ml
index 9e8d58b2..1e9dea8a 100644
--- a/tests/core/t_cbor.ml
+++ b/tests/core/t_cbor.ml
@@ -1,8 +1,6 @@
 include (val Containers_testlib.make ~__FILE__ ())
 module Cbor = Containers_cbor
 
-[@@@ifge 4.08]
-
 let gen_c : Cbor.t Q.Gen.t =
   let open Q.Gen in
   sized @@ fix
@@ -110,5 +108,3 @@ if not (c = c') then
   Q.Test.fail_reportf "@[<hv2>roundtrip failed:@ from %a@ to %a@]"
     Cbor.pp_diagnostic c Cbor.pp_diagnostic c';
 true
-
-[@@@endif]
diff --git a/tests/core/t_format.ml b/tests/core/t_format.ml
index c343a9c0..271b44b4 100644
--- a/tests/core/t_format.ml
+++ b/tests/core/t_format.ml
@@ -1,97 +1,158 @@
-
 open CCFormat
-
 module T = (val Containers_testlib.make ~__FILE__ ())
-include T;;
+include T
 
 let to_string_test s = CCFormat.sprintf_no_color "@[<h>%a@]%!" s ();;
 
-eq ~printer:(fun s->CCFormat.sprintf "%S" s) "a b" (to_string_test (return "a@ b"));;
-eq ~printer:(fun s->CCFormat.sprintf "%S" s) ", " (to_string_test (return ",@ "));;
-eq ~printer:(fun s->CCFormat.sprintf "%S" s) "and then" (to_string_test (return "@{<Red>and then@}@,"));;
-eq ~printer:(fun s->CCFormat.sprintf "%S" s) "a b" (to_string_test (return "@[<h>a@ b@]"));;
-
-
-eq ~printer:(fun s->CCFormat.sprintf "%S" s) "a\nb\nc"
-  (sprintf_no_color "@[<v>%a@]%!" text "a b c");;
-eq ~printer:(fun s->CCFormat.sprintf "%S" s) "a b\nc"
-  (sprintf_no_color "@[<h>%a@]%!" text "a b\nc");;
-
-
-eq ~printer:(fun s->CCFormat.sprintf "%S" s)
-  "(a\n b\n c)" (sprintf_no_color "(@[<v>%a@])" string_lines "a\nb\nc");;
-
-
-eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "foobar"
-  (to_string_test (append (return "foo") (return "bar")));;
-eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "bar"
-  (to_string_test (append (return "") (return "bar")));;
-eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "foo"
-  (to_string_test (append (return "foo") (return "")));;
-
-
-eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "" (to_string_test @@ append_l []);;
-eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "foobarbaz" (to_string_test @@ append_l (List.map return ["foo"; "bar"; "baz"]));;
-eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "3141" (to_string_test @@ append_l (List.map (const int) [3; 14; 1]));;
-
-t @@ fun () ->
-  let buf1 = Buffer.create 42 in
-  let buf2 = Buffer.create 42 in
-  let f1 = Format.formatter_of_buffer buf1 in
-  let f2 = Format.formatter_of_buffer buf2 in
-  let fmt = tee f1 f2 in
-  Format.fprintf fmt "coucou@.";
-  assert_equal ~printer:CCFun.id "coucou\n" (Buffer.contents buf1);
-  assert_equal ~printer:CCFun.id "coucou\n" (Buffer.contents buf2);
-  true;;
-
-[@@@ifge 4.8]
-
-t @@ fun () ->
-  set_color_default true;
-  let s = sprintf
-    "what is your %a? %a! No, %a! Ahhhhhhh@."
-    (styling [`FG `White; `Bold] string) "favorite color"
-    (styling [`FG `Blue] string) "blue"
-    (styling [`FG `Red] string) "red"
-  in
-  assert_equal ~printer:CCFun.id
-    "what is your \027[37;1mfavorite color\027[0m? \027[34mblue\027[0m! No, \027[31mred\027[0m! Ahhhhhhh\n"
-    s;
-    true
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "a b"
+  (to_string_test (return "a@ b"))
 ;;
 
-[@@@endif]
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  ", "
+  (to_string_test (return ",@ "))
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "and then"
+  (to_string_test (return "@{<Red>and then@}@,"))
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "a b"
+  (to_string_test (return "@[<h>a@ b@]"))
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "a\nb\nc"
+  (sprintf_no_color "@[<v>%a@]%!" text "a b c")
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "a b\nc"
+  (sprintf_no_color "@[<h>%a@]%!" text "a b\nc")
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "(a\n b\n c)"
+  (sprintf_no_color "(@[<v>%a@])" string_lines "a\nb\nc")
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "foobar"
+  (to_string_test (append (return "foo") (return "bar")))
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "bar"
+  (to_string_test (append (return "") (return "bar")))
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "foo"
+  (to_string_test (append (return "foo") (return "")))
+;;
+
+eq ~printer:(fun s -> CCFormat.sprintf "%S" s) "" (to_string_test @@ append_l [])
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "foobarbaz"
+  (to_string_test @@ append_l (List.map return [ "foo"; "bar"; "baz" ]))
+;;
+
+eq
+  ~printer:(fun s -> CCFormat.sprintf "%S" s)
+  "3141"
+  (to_string_test @@ append_l (List.map (const int) [ 3; 14; 1 ]))
+;;
 
 t @@ fun () ->
-  set_color_default true;
-  let s = sprintf
-    "what is your @{<White>favorite color@}? @{<blue>blue@}! No, @{<red>red@}! Ahhhhhhh@."
-  in
-  assert_equal ~printer:CCFun.id
-    "what is your \027[37;1mfavorite color\027[0m? \027[34mblue\027[0m! No, \027[31mred\027[0m! Ahhhhhhh\n"
-    s;
-    true;;
+let buf1 = Buffer.create 42 in
+let buf2 = Buffer.create 42 in
+let f1 = Format.formatter_of_buffer buf1 in
+let f2 = Format.formatter_of_buffer buf2 in
+let fmt = tee f1 f2 in
+Format.fprintf fmt "coucou@.";
+assert_equal ~printer:CCFun.id "coucou\n" (Buffer.contents buf1);
+assert_equal ~printer:CCFun.id "coucou\n" (Buffer.contents buf2);
+true
+;;
+
+t @@ fun () ->
+set_color_default true;
+let s =
+  sprintf "what is your %a? %a! No, %a! Ahhhhhhh@."
+    (styling [ `FG `White; `Bold ] string)
+    "favorite color"
+    (styling [ `FG `Blue ] string)
+    "blue"
+    (styling [ `FG `Red ] string)
+    "red"
+in
+assert_equal ~printer:CCFun.id
+  "what is your \027[37;1mfavorite color\027[0m? \027[34mblue\027[0m! No, \
+   \027[31mred\027[0m! Ahhhhhhh\n"
+  s;
+true
+;;
+
+t @@ fun () ->
+set_color_default true;
+let s =
+  sprintf
+    "what is your @{<White>favorite color@}? @{<blue>blue@}! No, @{<red>red@}! \
+     Ahhhhhhh@."
+in
+assert_equal ~printer:CCFun.id
+  "what is your \027[37;1mfavorite color\027[0m? \027[34mblue\027[0m! No, \
+   \027[31mred\027[0m! Ahhhhhhh\n"
+  s;
+true
+;;
 
 t @@ fun () -> sprintf "yolo %s %d" "a b" 42 = "yolo a b 42";;
 t @@ fun () -> sprintf "%d " 0 = "0 ";;
 t @@ fun () -> sprintf_no_color "%d " 0 = "0 ";;
 
 t @@ fun () ->
-  set_color_default true;
-  assert_equal "\027[31myolo\027[0m" (sprintf "@{<red>yolo@}");
-  assert_equal "yolo" (sprintf_no_color "@{<red>yolo@}");
-  true;;
+set_color_default true;
+assert_equal "\027[31myolo\027[0m" (sprintf "@{<red>yolo@}");
+assert_equal "yolo" (sprintf_no_color "@{<red>yolo@}");
+true
+;;
 
-eq ~printer:CCFormat.(to_string (opt string))
+eq
+  ~printer:CCFormat.(to_string (opt string))
   (Some "hello world")
-    (ksprintf ~f:(fun s -> Some s) "hello %a" CCFormat.string "world");;
+  (ksprintf ~f:(fun s -> Some s) "hello %a" CCFormat.string "world")
+;;
 
+eq ~printer:(fun s -> s) "[1;2;3]" (to_string Dump.(list int) [ 1; 2; 3 ]);;
+eq ~printer:(fun s -> s) "Some 1" (to_string Dump.(option int) (Some 1));;
 
-eq ~printer:(fun s->s) "[1;2;3]" (to_string Dump.(list int) [1;2;3]);;
-eq ~printer:(fun s->s) "Some 1" (to_string Dump.(option int) (Some 1));;
-eq ~printer:(fun s->s) "[None;Some \"a b\"]" (to_string Dump.(list (option string)) [None; Some "a b"]);;
-eq ~printer:(fun s->s) "[(Ok \"a b c\");(Error \"nope\")]"
-    (to_string Dump.(list (result string)) [Ok "a b c"; Error "nope"]);;
+eq
+  ~printer:(fun s -> s)
+  "[None;Some \"a b\"]"
+  (to_string Dump.(list (option string)) [ None; Some "a b" ])
+;;
 
-eq  ANSI_codes.reset "\x1b[0m";;
+eq
+  ~printer:(fun s -> s)
+  "[(Ok \"a b c\");(Error \"nope\")]"
+  (to_string Dump.(list (result string)) [ Ok "a b c"; Error "nope" ])
+;;
+
+eq ANSI_codes.reset "\x1b[0m"
diff --git a/tests/core/t_string.ml b/tests/core/t_string.ml
index 25177658..44d8dd72 100644
--- a/tests/core/t_string.ml
+++ b/tests/core/t_string.ml
@@ -1,7 +1,7 @@
 module T = (val Containers_testlib.make ~__FILE__ ())
 include T
 open CCString
-open CCShims_.Stdlib;;
+.Stdlib;;
 
 q Q.printable_string (fun s -> s = rev (rev s));;
 q Q.printable_string (fun s -> length s = length (rev s));;