diff --git a/src/core/CCString.ml b/src/core/CCString.ml
index 9805cea1..a0f6ba89 100644
--- a/src/core/CCString.ml
+++ b/src/core/CCString.ml
@@ -10,33 +10,6 @@ type 'a gen = unit -> 'a option
 type 'a sequence = ('a -> unit) -> unit
 type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 
-(* compatibility implementations *)
-
-let init n f =
-  let buf = Bytes.init n f in
-  Bytes.unsafe_to_string buf
-
-(*$T
-  init 3 (fun i -> [|'a'; 'b'; 'c'|].(i)) = "abc"
-  init 0 (fun _ -> assert false) = ""
-*)
-
-let uppercase_ascii = String.map CCChar.uppercase_ascii
-
-let lowercase_ascii = String.map CCChar.lowercase_ascii
-
-let mapi f s = init (String.length s) (fun i -> f i s.[i])
-
-let capitalize_ascii s =
-  mapi
-    (fun i c -> if i=0 then CCChar.uppercase_ascii c else c)
-    s
-
-let uncapitalize_ascii s =
-  mapi
-    (fun i c -> if i=0 then CCChar.lowercase_ascii c else c)
-    s
-
 (* standard implementations *)
 
 include String
@@ -100,8 +73,6 @@ module type S = sig
       Renamed from [print] since 2.0. *)
 end
 
-let equal (a:string) b = Stdlib.(=) a b
-
 let compare_int (a : int) b = Stdlib.compare a b
 let compare = String.compare
 
diff --git a/src/core/CCString.mli b/src/core/CCString.mli
index 12641bae..5a5baa97 100644
--- a/src/core/CCString.mli
+++ b/src/core/CCString.mli
@@ -82,9 +82,6 @@ end
 
 include module type of struct include String end
 
-val equal : string -> string -> bool
-(** Equality function on strings. *)
-
 val compare : string -> string -> int
 
 val is_empty : string -> bool
@@ -93,10 +90,6 @@ val is_empty : string -> bool
 
 val hash : string -> int
 
-val init : int -> (int -> char) -> string
-(** Like [Array.init].
-    @since 0.3.3 *)
-
 val rev : string -> string
 (** [rev s] returns the reverse of [s].
     @since 0.17 *)
@@ -244,18 +237,6 @@ val iter : (char -> unit) -> string -> unit
 (** Alias to {!String.iter}.
     @since 0.12 *)
 
-val iteri : (int -> char -> unit) -> string -> unit
-(** Iter on chars with their index.
-    @since 0.12 *)
-
-val map : (char -> char) -> string -> string
-(** Map chars.
-    @since 0.12 *)
-
-val mapi : (int -> char -> char) -> string -> string
-(** Map chars with their index.
-    @since 0.12 *)
-
 val filter_map : (char -> char option) -> string -> string
 (** [filter_map f s] calls [(f a0) (f a1) ... (f an)] where [a0 ... an] are the characters of s.
     It returns the string of characters [ci] such as [f ai = Some ci] (when [f] returns [None],
@@ -336,22 +317,6 @@ val exists2 : (char -> char -> bool) -> string -> string -> bool
     Those functions are deprecated in {!String} since 4.03, so we provide
     a stable alias for them even in older versions. *)
 
-val capitalize_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
-val uncapitalize_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
-val uppercase_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
-val lowercase_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
 val equal_caseless : string -> string -> bool
 (** Comparison without respect to {b ascii} lowercase.
     @since 1.2 *)
diff --git a/src/core/CCStringLabels.mli b/src/core/CCStringLabels.mli
index d3d2c18b..a4dce45a 100644
--- a/src/core/CCStringLabels.mli
+++ b/src/core/CCStringLabels.mli
@@ -79,9 +79,6 @@ end
 
 include module type of struct include StringLabels end
 
-val equal : string -> string -> bool
-(** Equality function on strings. *)
-
 val compare : string -> string -> int
 
 val is_empty : string -> bool
@@ -90,10 +87,6 @@ val is_empty : string -> bool
 
 val hash : string -> int
 
-val init : int -> (int -> char) -> string
-(** Like [Array.init].
-    @since 0.3.3 *)
-
 val rev : string -> string
 (** [rev s] returns the reverse of [s].
     @since 0.17 *)
@@ -241,18 +234,6 @@ val iter : f:(char -> unit) -> string -> unit
 (** Alias to {!String.iter}.
     @since 0.12 *)
 
-val iteri : f:(int -> char -> unit) -> string -> unit
-(** Iter on chars with their index.
-    @since 0.12 *)
-
-val map : f:(char -> char) -> string -> string
-(** Map chars.
-    @since 0.12 *)
-
-val mapi : f:(int -> char -> char) -> string -> string
-(** Map chars with their index.
-    @since 0.12 *)
-
 val filter_map : f:(char -> char option) -> string -> string
 (** [filter_map f s] calls [(f a0) (f a1) ... (f an)] where [a0 ... an] are the characters of s.
     It returns the string of characters [ci] such as [f ai = Some ci] (when [f] returns [None],
@@ -333,22 +314,6 @@ val exists2 : f:(char -> char -> bool) -> string -> string -> bool
     Those functions are deprecated in {!String} since 4.03, so we provide
     a stable alias for them even in older versions. *)
 
-val capitalize_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
-val uncapitalize_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
-val uppercase_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
-val lowercase_ascii : string -> string
-(** See {!String}.
-    @since 0.18 *)
-
 val equal_caseless : string -> string -> bool
 (** Comparison without respect to {b ascii} lowercase.
     @since 1.2 *)