diff --git a/src/client/opamAuxCommands.ml b/src/client/opamAuxCommands.ml
index 6002864c0bf..3294f9e4dd1 100644
--- a/src/client/opamAuxCommands.ml
+++ b/src/client/opamAuxCommands.ml
@@ -492,13 +492,13 @@ let get_compatible_compiler ?repos rt dir =
        (OpamStd.Format.itemize OpamPackage.to_string
           (OpamPackage.Set.elements local_packages));
      if OpamConsole.confirm "Do you want to create an empty switch regardless?"
-     then [], false
+     then None, false
      else OpamStd.Sys.exit_because `Aborted)
   else
   let compilers = OpamPackage.Set.inter compilers installable in
   try
-    [OpamSolution.eq_atom_of_package
-       (OpamPackage.Set.choose_one compilers)], true
+    Some (OpamSolution.eq_atom_of_package
+       (OpamPackage.Set.choose_one compilers)), true
   with
   | Not_found when not (OpamPackage.Set.is_empty local_packages) ->
     OpamConsole.warning
@@ -508,7 +508,7 @@ let get_compatible_compiler ?repos rt dir =
        OpamConsole.confirm
          "Create the switch with no specific compiler selected, and attempt to \
           continue?"
-    then [], false
+    then None, false
     else OpamStd.Sys.exit_because `Aborted
  | Failure _ | Not_found ->
    (* Find a matching compiler from the default selection *)
@@ -516,37 +516,54 @@ let get_compatible_compiler ?repos rt dir =
      OpamFile.Config.default_compiler gt.config
    in
    if default_compiler = Empty then
-     (OpamConsole.warning "No compiler selected"; [], false)
+     (OpamConsole.warning "No compiler selected"; None, false)
    else
    let candidates = OpamFormula.to_dnf default_compiler in
    try
-     OpamStd.List.find_map
-       (fun atoms ->
-          let has_all compiler_packages =
-            List.for_all (fun at ->
-                OpamPackage.Set.exists (OpamFormula.check at) compiler_packages)
-              atoms
-          in
-          let compiler =
-            OpamFormula.packages_of_atoms
-              (Lazy.force virt_st.available_packages)
-              atoms
-          in
-          if not (has_all compiler) then None else
-          if OpamPackage.Set.is_empty local_packages then
-            Some (OpamSolution.eq_atoms_of_packages compiler)
-          else
-          (* fake universe with `local_packages` as base, just to check
-             coinstallability *)
-          let univ =
-            { univ with u_base = local_packages; u_installed = local_packages }
-          in
-          let compiler = OpamSolver.installable_subset univ compiler in
-          if has_all compiler then
-            Some (OpamSolution.eq_atoms_of_packages compiler)
-          else None
-       )
-       candidates, false
+     let candidates =
+       OpamStd.List.find_map
+         (fun atoms ->
+            let has_all compiler_packages =
+              List.for_all (fun at ->
+                  OpamPackage.Set.exists (OpamFormula.check at) compiler_packages)
+                atoms
+            in
+            let compiler =
+              OpamFormula.packages_of_atoms
+                (Lazy.force virt_st.available_packages)
+                atoms
+            in
+            if not (has_all compiler) then None else
+            if OpamPackage.Set.is_empty local_packages then
+              Some (OpamSolution.eq_atoms_of_packages compiler)
+            else
+            (* fake universe with `local_packages` as base, just to check
+               coinstallability *)
+            let univ =
+              { univ with u_base = local_packages; u_installed = local_packages }
+            in
+            let compiler = OpamSolver.installable_subset univ compiler in
+            if has_all compiler then
+              Some (OpamSolution.eq_atoms_of_packages compiler)
+            else None
+         ) candidates
+     in
+     let candidate =
+       candidates
+       |> List.map (fun (n,vc) ->
+           OpamPackage.create n
+             (match vc with
+              | Some (`Eq, v) -> v
+              (* all atoms are from [OpamFormula.eq_atoms_of_packages] *)
+              | _ -> assert false))
+       |> OpamPackage.Set.of_list
+       |> (fun s ->
+           OpamPackage.(max_version s
+                          (names_of_packages s
+                           |> Name.Set.choose)))
+       |> fun p -> Some (OpamSolution.eq_atom_of_package p)
+     in
+     candidate,false
    with Not_found ->
       OpamConsole.warning
         "The default compiler selection: %s\n\
@@ -558,5 +575,5 @@ let get_compatible_compiler ?repos rt dir =
       if OpamConsole.confirm
           "You may also proceed, with no specific compiler selected. \
            Do you want to?"
-      then [], false
+      then None, false
       else OpamStd.Sys.exit_because `Aborted
diff --git a/src/client/opamAuxCommands.mli b/src/client/opamAuxCommands.mli
index 570809bb5f1..0ad7352d88a 100644
--- a/src/client/opamAuxCommands.mli
+++ b/src/client/opamAuxCommands.mli
@@ -91,4 +91,4 @@ val simulate_autopin:
     warning, and returns the empty list after user confirmation. *)
 val get_compatible_compiler:
   ?repos:repository_name list ->
-  'a repos_state -> dirname -> atom list * bool
+  'a repos_state -> dirname -> atom option * bool
diff --git a/src/client/opamCommands.ml b/src/client/opamCommands.ml
index e08a1f999b7..8c99f793a1a 100644
--- a/src/client/opamCommands.ml
+++ b/src/client/opamCommands.ml
@@ -380,6 +380,7 @@ let init =
     | Some comp when String.length comp <> 0->
       let packages =
         OpamSwitchCommand.guess_compiler_package rt comp
+        |> OpamStd.Option.map_default (fun x -> [x]) []
       in
       OpamConsole.header_msg "Creating initial switch (%s)"
         (OpamFormula.string_of_atoms packages);
@@ -2085,17 +2086,22 @@ let switch =
     let compiler_packages rt ?repos switch compiler_opt =
       match packages, compiler_opt, OpamSwitch.is_external switch with
       | None, None, false ->
-        OpamSwitchCommand.guess_compiler_package ?repos rt
-          (OpamSwitch.to_string switch), false
+        OpamStd.Option.to_list
+          (OpamSwitchCommand.guess_compiler_package ?repos rt
+             (OpamSwitch.to_string switch)), false
       | None, None, true ->
-        OpamAuxCommands.get_compatible_compiler ?repos rt
-          (OpamFilename.dirname_dir
-             (OpamSwitch.get_root rt.repos_global.root switch))
+        let p, local =
+          OpamAuxCommands.get_compatible_compiler ?repos rt
+            (OpamFilename.dirname_dir
+               (OpamSwitch.get_root rt.repos_global.root switch))
+        in
+        OpamStd.Option.to_list p, local
       | _ ->
-        OpamStd.Option.Op.(
-          ((compiler_opt >>|
-            OpamSwitchCommand.guess_compiler_package ?repos rt) +! []) @
-          packages +! []), false
+        let open OpamStd.Option.Op in
+        (OpamStd.Option.to_list
+           (compiler_opt >>=
+            OpamSwitchCommand.guess_compiler_package ?repos rt))
+        @ packages +! [], false
     in
     let param_compiler = function
       | [] -> None
diff --git a/src/client/opamSolution.mli b/src/client/opamSolution.mli
index fc6c1424591..528ad241b19 100644
--- a/src/client/opamSolution.mli
+++ b/src/client/opamSolution.mli
@@ -66,7 +66,7 @@ val check_solution:
 (** Return an atom with a strict version constraint *)
 val eq_atom: name -> version -> atom
 
-(** Return a simple atom, with no version constrain, from a package*)
+(** Return a simple atom, with no version constraint, from a package*)
 val atom_of_package: package -> atom
 
 (** Returns an atom with a strict version constraint from a package *)
diff --git a/src/client/opamSwitchCommand.ml b/src/client/opamSwitchCommand.ml
index bba7abadeeb..731737930c8 100644
--- a/src/client/opamSwitchCommand.ml
+++ b/src/client/opamSwitchCommand.ml
@@ -665,7 +665,7 @@ let guess_compiler_package ?repos rt name =
   in
   match OpamPackage.of_string_opt name with
   | Some nv when OpamPackage.Set.mem nv compiler_packages ->
-    [OpamSolution.eq_atom_of_package nv]
+    Some (OpamSolution.eq_atom_of_package nv)
   | Some nv when OpamRepositoryState.find_package_opt rt repos nv <> None ->
     advise_compiler_dependencies rt opams compiler_packages name
       [OpamSolution.eq_atom_of_package nv];
@@ -677,7 +677,7 @@ let guess_compiler_package ?repos rt name =
     in
     match pkgname with
     | Some pkgname when OpamPackage.has_name compiler_packages pkgname ->
-      [pkgname, None]
+      Some (pkgname, None)
     | Some pkgname when
         OpamPackage.Map.exists (fun nv _ -> OpamPackage.name nv = pkgname) opams
       ->
@@ -691,8 +691,8 @@ let guess_compiler_package ?repos rt name =
           compiler_packages
       in
       try
-        [OpamSolution.eq_atom_of_package
-           (OpamPackage.Set.choose_one has_version)]
+        Some (OpamSolution.eq_atom_of_package
+           (OpamPackage.Set.choose_one has_version))
       with
       | Not_found -> no_compiler_error ()
       | Failure _ ->
diff --git a/src/client/opamSwitchCommand.mli b/src/client/opamSwitchCommand.mli
index cfd910f6b22..17a510a12b6 100644
--- a/src/client/opamSwitchCommand.mli
+++ b/src/client/opamSwitchCommand.mli
@@ -72,4 +72,4 @@ val get_compiler_packages:
     match [name] against "pkg.version", "pkg", and, as a last resort,
     "version" (for compat with older opams, eg. 'opam switch 4.02.3') *)
 val guess_compiler_package:
-  ?repos:repository_name list -> 'a repos_state -> string -> atom list
+  ?repos:repository_name list -> 'a repos_state -> string -> atom option
diff --git a/src/core/opamStd.ml b/src/core/opamStd.ml
index 8b45886e58f..7993189f16e 100644
--- a/src/core/opamStd.ml
+++ b/src/core/opamStd.ml
@@ -407,6 +407,10 @@ module Option = struct
     | Some x -> f x
     | None -> none
 
+  let to_list = function
+    | None -> []
+    | Some x -> [x]
+
   let some x = Some x
   let none _ = None
 
diff --git a/src/core/opamStd.mli b/src/core/opamStd.mli
index 6bdb9504645..c662b823654 100644
--- a/src/core/opamStd.mli
+++ b/src/core/opamStd.mli
@@ -139,6 +139,8 @@ module Option: sig
 
   val to_string: ?none:string -> ('a -> string) -> 'a option -> string
 
+  val to_list: 'a option -> 'a list
+
   val some: 'a -> 'a option
 
   val none: 'a -> 'b option