diff --git a/bin/dune_init.ml b/bin/dune_init.ml
index 945925ad4c11..1621e04ad8f9 100644
--- a/bin/dune_init.ml
+++ b/bin/dune_init.ml
@@ -195,6 +195,64 @@ module Init_context = struct
   ;;
 end
 
+module Public_name = struct
+  module Pkg = Dune_lang.Package_name.Opam_compatible
+
+  module T = struct
+    type t =
+      { pkg : Pkg.t
+      ; sub : string list
+      }
+
+    let module_ = "Dune_init.Public_name"
+    let description = "public name"
+
+    let description_of_valid_string =
+      let open Pp.O in
+      Some
+        (Pp.text
+           "Public names are composed of an opam package name and optional dot-separated \
+            string suffixes."
+         ++ Pp.newline
+         ++ Pkg.description_of_valid_string)
+    ;;
+
+    let split s =
+      match String.split s ~on:'.' with
+      | [] -> assert false
+      | pkg_s :: sub -> pkg_s, sub
+    ;;
+
+    let join pkg_s sub = String.concat ~sep:"." (pkg_s :: sub)
+
+    let make_valid s =
+      let pkg_s, sub = split s in
+      let pkg_fixed = Pkg.make_valid pkg_s in
+      join pkg_fixed sub
+    ;;
+
+    let hint_valid = Some make_valid
+
+    let of_string_opt s =
+      let open Option.O in
+      let pkg_s, sub = split s in
+      let+ pkg = Pkg.of_string_opt pkg_s in
+      { pkg; sub }
+    ;;
+
+    let to_string { pkg; sub } = join (Pkg.to_string pkg) sub
+  end
+
+  include T
+  include Dune_util.Stringlike.Make (T)
+
+  let of_name_exn name =
+    let s = Dune_lang.Atom.to_string name in
+    let pkg = Pkg.of_string_user_error (Loc.none, s) |> User_error.ok_exn in
+    { pkg; sub = [] }
+  ;;
+end
+
 module Component = struct
   module Options = struct
     module Common = struct
@@ -206,12 +264,12 @@ module Component = struct
     end
 
     module Executable = struct
-      type t = { public : Dune_lang.Atom.t option }
+      type t = { public : Public_name.t option }
     end
 
     module Library = struct
       type t =
-        { public : Dune_lang.Atom.t option
+        { public : Public_name.t option
         ; inline_tests : bool
         }
     end
@@ -308,8 +366,7 @@ module Component = struct
       if List.mem ~equal:Dune_lang.Atom.equal set elem then set else elem :: set
     ;;
 
-    let public_name_encoder atom = Atom atom
-    let public_name_field = Encoder.field_o "public_name" public_name_encoder
+    let public_name_field = Encoder.field_o "public_name" Public_name.encode
 
     let executable (common : Options.Common.t) (options : Options.Executable.t) =
       make "executable" common [ public_name_field options.public ]
@@ -438,7 +495,7 @@ module Component = struct
         let libraries = Stanza_cst.add_to_list_set common.name common.libraries in
         bin
           { context = { context with dir = Path.relative dir "bin" }
-          ; options = { public = Some common.name }
+          ; options = { public = Some (Public_name.of_name_exn common.name) }
           ; common = { common with libraries; name = Dune_lang.Atom.of_string "main" }
           }
       in
@@ -449,7 +506,10 @@ module Component = struct
       let lib_target =
         src
           { context = { context with dir = Path.relative dir "lib" }
-          ; options = { public = Some common.name; inline_tests = options.inline_tests }
+          ; options =
+              { public = Some (Public_name.of_name_exn common.name)
+              ; inline_tests = options.inline_tests
+              }
           ; common
           }
       in
diff --git a/bin/dune_init.mli b/bin/dune_init.mli
index 1d959e513727..b69826b6411a 100644
--- a/bin/dune_init.mli
+++ b/bin/dune_init.mli
@@ -12,6 +12,12 @@ module Init_context : sig
   val make : string option -> t Memo.t
 end
 
+module Public_name : sig
+  include Dune_util.Stringlike
+
+  val of_name_exn : Dune_lang.Atom.t -> t
+end
+
 (** A [Component.t] is a set of files that can be built or included as part of a
     build. *)
 module Component : sig
@@ -28,13 +34,13 @@ module Component : sig
 
     (** Options for executable components *)
     module Executable : sig
-      type t = { public : Dune_lang.Atom.t option }
+      type t = { public : Public_name.t option }
     end
 
     (** Options for library components *)
     module Library : sig
       type t =
-        { public : Dune_lang.Atom.t option
+        { public : Public_name.t option
         ; inline_tests : bool
         }
     end
diff --git a/bin/init.ml b/bin/init.ml
index e9b1c943b012..d843fe107d0b 100644
--- a/bin/init.ml
+++ b/bin/init.ml
@@ -79,23 +79,27 @@ let context_cwd : Init_context.t Term.t =
 module Public_name = struct
   type t =
     | Use_name
-    | Public_name of Dune_lang.Atom.t
+    | Public_name of Public_name.t
 
   let public_name_to_string = function
     | Use_name -> "<default>"
-    | Public_name p -> Dune_lang.Atom.to_string p
+    | Public_name p -> Public_name.to_string p
   ;;
 
   let public_name (common : Component.Options.Common.t) = function
     | None -> None
-    | Some Use_name -> Some common.name
+    | Some Use_name -> Some (Public_name.of_name_exn common.name)
     | Some (Public_name n) -> Some n
   ;;
 
   let conv =
-    let parser = function
-      | "" -> Ok Use_name
-      | s -> component_name_parser s |> Result.map ~f:(fun a -> Public_name a)
+    let parser s =
+      if String.is_empty s
+      then Ok Use_name
+      else (
+        match Public_name.of_string_user_error (Loc.none, s) with
+        | Ok n -> Ok (Public_name n)
+        | Error e -> Error (`Msg (User_message.to_string e)))
     in
     let printer ppf public_name =
       Format.pp_print_string ppf (public_name_to_string public_name)
diff --git a/src/dune_lang/package_name.ml b/src/dune_lang/package_name.ml
index 2f5e6ae95607..e4220650d4b2 100644
--- a/src/dune_lang/package_name.ml
+++ b/src/dune_lang/package_name.ml
@@ -15,47 +15,50 @@ include (
     Dune_util.Stringlike with type t := t)
 
 module Opam_compatible = struct
-  include Dune_util.Stringlike.Make (struct
-      type t = string
+  let description_of_valid_string =
+    Pp.text
+      "Package names can contain letters, numbers, '-', '_' and '+', and need to contain \
+       at least a letter."
+  ;;
 
-      let module_ = "Package.Name.Strict"
-      let description = "opam package name"
-      let to_string s = s
+  module T = struct
+    type t = string
+
+    let module_ = "Package.Name.Strict"
+    let description = "opam package name"
+    let to_string s = s
+    let description_of_valid_string = Some description_of_valid_string
 
-      let description_of_valid_string =
-        Some
-          (Pp.textf
-             "Package names can contain letters, numbers, '-', '_' and '+', and need to \
-              contain at least a letter.")
-      ;;
+    let is_letter = function
+      | 'a' .. 'z' | 'A' .. 'Z' -> true
+      | _ -> false
+    ;;
 
-      let is_letter = function
-        | 'a' .. 'z' | 'A' .. 'Z' -> true
-        | _ -> false
-      ;;
+    let is_other_valid_char = function
+      | '0' .. '9' | '-' | '+' | '_' -> true
+      | _ -> false
+    ;;
 
-      let is_other_valid_char = function
-        | '0' .. '9' | '-' | '+' | '_' -> true
-        | _ -> false
-      ;;
+    let is_valid_char c = is_letter c || is_other_valid_char c
 
-      let is_valid_char c = is_letter c || is_other_valid_char c
+    let is_valid_string s =
+      let all_chars_valid = String.for_all s ~f:is_valid_char in
+      let has_one_letter = String.exists s ~f:is_letter in
+      all_chars_valid && has_one_letter
+    ;;
 
-      let is_valid_string s =
-        let all_chars_valid = String.for_all s ~f:is_valid_char in
-        let has_one_letter = String.exists s ~f:is_letter in
-        all_chars_valid && has_one_letter
-      ;;
+    let of_string_opt s = Option.some_if (is_valid_string s) s
 
-      let of_string_opt s = Option.some_if (is_valid_string s) s
+    let make_valid s =
+      let replaced = String.map s ~f:(fun c -> if is_valid_char c then c else '_') in
+      if is_valid_string replaced then replaced else "p" ^ replaced
+    ;;
 
-      let make_valid s =
-        let replaced = String.map s ~f:(fun c -> if is_valid_char c then c else '_') in
-        if is_valid_string replaced then replaced else "p" ^ replaced
-      ;;
+    let hint_valid = Some make_valid
+  end
 
-      let hint_valid = Some make_valid
-    end)
+  include Dune_util.Stringlike.Make (T)
 
+  let make_valid = T.make_valid
   let to_package_name s = s
 end
diff --git a/src/dune_lang/package_name.mli b/src/dune_lang/package_name.mli
index 6849029cd58e..4b7b5847f67a 100644
--- a/src/dune_lang/package_name.mli
+++ b/src/dune_lang/package_name.mli
@@ -20,5 +20,7 @@ module Opam_compatible : sig
     type package_name
 
     val to_package_name : t -> package_name
+    val description_of_valid_string : _ Pp.t
+    val make_valid : string -> string
   end
   with type package_name := t
diff --git a/test/blackbox-tests/test-cases/dune-init/github7108.t b/test/blackbox-tests/test-cases/dune-init/github7108.t
index 61388f2f2ab5..44e395d0942e 100644
--- a/test/blackbox-tests/test-cases/dune-init/github7108.t
+++ b/test/blackbox-tests/test-cases/dune-init/github7108.t
@@ -1,10 +1,4 @@
 #7108: foo-bar is a valid public name, we should accept it.
 
   $ dune init lib foo_bar --public foo-bar
-  dune: option '--public': invalid component name `foo-bar'
-        Library names must be non-empty and composed only of the
-        following
-        characters: 'A'..'Z', 'a'..'z', '_' or '0'..'9'.
-  Usage: dune init library [OPTION]… NAME [PATH]
-  Try 'dune init library --help' or 'dune --help' for more information.
-  [1]
+  Success: initialized library component named foo_bar
diff --git a/test/blackbox-tests/test-cases/dune-init/public-implicit-invalid.t b/test/blackbox-tests/test-cases/dune-init/public-implicit-invalid.t
new file mode 100644
index 000000000000..32052286f44b
--- /dev/null
+++ b/test/blackbox-tests/test-cases/dune-init/public-implicit-invalid.t
@@ -0,0 +1,9 @@
+When a public name is implicit from the name, it should still be validated as a
+public name.
+
+  $ dune init lib 0 --public
+  Error: "0" is an invalid opam package name.
+  Package names can contain letters, numbers, '-', '_' and '+', and need to
+  contain at least a letter.
+  Hint: p0 would be a correct opam package name
+  [1]
diff --git a/test/blackbox-tests/test-cases/dune-init/public-sublibrary.t b/test/blackbox-tests/test-cases/dune-init/public-sublibrary.t
index 9507ea99da0d..3dbb9d3dd763 100644
--- a/test/blackbox-tests/test-cases/dune-init/public-sublibrary.t
+++ b/test/blackbox-tests/test-cases/dune-init/public-sublibrary.t
@@ -1,10 +1,4 @@
 Sub-library names should be accepted:
 
   $ dune init lib lib_s1_s2 --public lib.sub1.sub2
-  dune: option '--public': invalid component name `lib.sub1.sub2'
-        Library names must be non-empty and composed only of the
-        following
-        characters: 'A'..'Z', 'a'..'z', '_' or '0'..'9'.
-  Usage: dune init library [OPTION]… NAME [PATH]
-  Try 'dune init library --help' or 'dune --help' for more information.
-  [1]
+  Success: initialized library component named lib_s1_s2
diff --git a/test/blackbox-tests/test-cases/github3046.t b/test/blackbox-tests/test-cases/github3046.t
index cfb9536e1f05..6f9da1dcb5b6 100644
--- a/test/blackbox-tests/test-cases/github3046.t
+++ b/test/blackbox-tests/test-cases/github3046.t
@@ -25,10 +25,15 @@ are given as parameters
 `dune init lib foo --public="some/invalid&name!"` returns an informative parsing error
 
   $ dune init lib foo --public="some/invalid&name!"
-  dune: option '--public': invalid component name `some/invalid&name!'
-        Library names must be non-empty and composed only of the
-        following
-        characters: 'A'..'Z', 'a'..'z', '_' or '0'..'9'.
+  dune: option '--public': "some/invalid&name!" is an invalid public
+        name.
+        Public names are composed of an opam package name and optional
+        dot-separated
+        string suffixes.
+        Package names can contain letters, numbers, '-', '_' and '+', and need
+        to
+        contain at least a letter.
+        Hint: some_invalid_name_ would be a correct public name
   Usage: dune init library [OPTION]… NAME [PATH]
   Try 'dune init library --help' or 'dune --help' for more information.
   [1]