diff --git a/include/parse_config.ml b/include/parse_config.ml
index 0669f39e..5a0b6a98 100644
--- a/include/parse_config.ml
+++ b/include/parse_config.ml
@@ -120,37 +120,39 @@ let parse s =
   | Error msg -> Fmt.failwith "config parse error: %s" msg
   | Ok v -> fold_sections v
 
-let pp_item ppf { key; value } =
-  let open Fmt in
-  match String.contains value '"' || String.contains value ' ' with
-  | false -> pf ppf "%s = %s" key value
-  | true -> pf ppf "%s = \"%s\"" key value
+module Pp_debug = struct
+  let pp_item ppf { key; value } =
+    let open Fmt in
+    match String.contains value '"' || String.contains value ' ' with
+    | false -> pf ppf "%s = %s" key value
+    | true -> pf ppf "%s = \"%s\"" key value
 
-let pp_line ppf line =
-  let open Fmt in
-  match line with
-  | Blank -> Fmt.nop ppf ()
-  | Comment s -> pf ppf "#%s" s
-  | Header s -> pf ppf "[%s]" s
-  | Item item -> pf ppf "%a" pp_item item
+  let pp_line ppf line =
+    let open Fmt in
+    match line with
+    | Blank -> Fmt.nop ppf ()
+    | Comment s -> pf ppf "#%s" s
+    | Header s -> pf ppf "[%s]" s
+    | Item item -> pf ppf "%a" pp_item item
 
-let _pp_lines ppf raw_line_l =
-  let open Fmt in
-  pf ppf "%a" (list ~sep:(any "\n") pp_line) raw_line_l
+  let _pp_lines ppf raw_line_l =
+    let open Fmt in
+    pf ppf "%a" (list ~sep:(any "\n") pp_line) raw_line_l
 
-let pp_section ppf { header; items } =
-  let open Fmt in
-  pf ppf "[%s]@\n%a" header (list ~sep:(any "\n") pp_item) items
+  let pp_section ppf { header; items } =
+    let open Fmt in
+    pf ppf "[%s]@\n%a" header (list ~sep:(any "\n") pp_item) items
 
-let pp_config ppf l =
-  let open Fmt in
-  pf ppf "%a" (list ~sep:(any "\n") pp_section) l
+  let pp_config ppf l =
+    let open Fmt in
+    pf ppf "%a" (list ~sep:(any "\n") pp_section) l
+end
 
 let () =
   let content = read_file "default.config" in
   (*Fmt.pr "%s" content;*)
   let config = parse content in
   (*Fmt.pr "%a@." pp_lines config;*)
-  Fmt.pr "%a@." pp_config config;
+  Fmt.pr "%a@." Pp_debug.pp_config config;
 
   ()