diff --git a/src/dune_engine/section.ml b/src/dune_engine/section.ml
index dd04a532ec56..b16e22b6f07d 100644
--- a/src/dune_engine/section.ml
+++ b/src/dune_engine/section.ml
@@ -3,23 +3,30 @@ include Dune_section
 
 let compare : t -> t -> Ordering.t = Poly.compare
 
+let allmap =
+  [ ("lib", Lib)
+  ; ("lib_root", Lib_root)
+  ; ("libexec", Libexec)
+  ; ("libexec_root", Libexec_root)
+  ; ("bin", Bin)
+  ; ("sbin", Sbin)
+  ; ("toplevel", Toplevel)
+  ; ("share", Share)
+  ; ("share_root", Share_root)
+  ; ("etc", Etc)
+  ; ("doc", Doc)
+  ; ("stublibs", Stublibs)
+  ; ("man", Man)
+  ; ("misc", Misc)
+  ]
+
 let to_dyn x =
+  let s =
+    List.find_map ~f:(fun (s, v) -> Option.some_if (x = v) s) allmap
+    |> Option.value_exn
+  in
   let open Dyn.Encoder in
-  match x with
-  | Lib -> constr "Lib" []
-  | Lib_root -> constr "Lib_root" []
-  | Libexec -> constr "Libexec" []
-  | Libexec_root -> constr "Libexec_root" []
-  | Bin -> constr "Bin" []
-  | Sbin -> constr "Sbin" []
-  | Toplevel -> constr "Toplevel" []
-  | Share -> constr "Share" []
-  | Share_root -> constr "Share_root" []
-  | Etc -> constr "Etc" []
-  | Doc -> constr "Doc" []
-  | Stublibs -> constr "Stublibs" []
-  | Man -> constr "Man" []
-  | Misc -> constr "Misc" []
+  constr (String.uppercase_ascii s) []
 
 module Key = struct
   type nonrec t = t
@@ -40,44 +47,13 @@ let parse_string s =
 
 let decode =
   let open Dune_lang.Decoder in
-  enum
-    [ ("lib", Lib)
-    ; ("lib_root", Lib_root)
-    ; ("libexec", Libexec)
-    ; ("libexec_root", Libexec_root)
-    ; ("bin", Bin)
-    ; ("sbin", Sbin)
-    ; ("toplevel", Toplevel)
-    ; ("share", Share)
-    ; ("share_root", Share_root)
-    ; ("etc", Etc)
-    ; ("doc", Doc)
-    ; ("stublibs", Stublibs)
-    ; ("man", Man)
-    ; ("misc", Misc)
-    ]
+  enum allmap
 
 let encode v =
   let open Dune_lang.Encoder in
   string (to_string v)
 
-let all =
-  Set.of_list
-    [ Lib
-    ; Lib_root
-    ; Libexec
-    ; Libexec_root
-    ; Bin
-    ; Sbin
-    ; Toplevel
-    ; Share
-    ; Share_root
-    ; Etc
-    ; Doc
-    ; Stublibs
-    ; Man
-    ; Misc
-    ]
+let all = Set.of_list (List.map ~f:snd allmap)
 
 let should_set_executable_bit = function
   | Lib