diff --git a/sw/ground_segment/cockpit/editFP.ml b/sw/ground_segment/cockpit/editFP.ml
index 8c0e90213b..3a3673736f 100644
--- a/sw/ground_segment/cockpit/editFP.ml
+++ b/sw/ground_segment/cockpit/editFP.ml
@@ -51,10 +51,8 @@ let save_fp = fun geomap ->
         | Some file ->
           let f  = open_out file in
           let fp_path = Str.replace_first (Str.regexp Env.flight_plans_path) "" (Filename.dirname file) in
-          let l = Str.split (Str.regexp Filename.dir_sep) fp_path in
-          let rel_path = String.concat Filename.dir_sep (Array.to_list (Array.make (List.length l) Filename.parent_dir_name)) in
-          let fp_dtd = rel_path // "flight_plan.dtd" in
-          fprintf f "<!DOCTYPE flight_plan SYSTEM \"%s\">\n\n" fp_dtd;
+          let rel_path = Str.global_replace (Str.regexp (Printf.sprintf "%s[^%s]+" Filename.dir_sep Filename.dir_sep)) (Filename.parent_dir_name // "") fp_path in
+          fprintf f "<!DOCTYPE flight_plan SYSTEM \"%s%s\">\n\n" rel_path "flight_plan.dtd";
           fprintf f "%s\n" (ExtXml.to_string_fmt fp#xml);
           close_out f;
           current_fp := Some (fp, file);
diff --git a/sw/tools/gen_airframe.ml b/sw/tools/gen_airframe.ml
index 8e066b3ec4..d18fead422 100644
--- a/sw/tools/gen_airframe.ml
+++ b/sw/tools/gen_airframe.ml
@@ -281,7 +281,7 @@ let rec parse_section = fun ac_id s ->
       List.iter (fun d -> printf "  Actuators%sInit();\\\n" d) drivers;
       printf "}\n\n";
     | "include" ->
-      let filename = Str.global_replace (Str.regexp "\$AC_ID") ac_id (ExtXml.attrib s "href") in
+      let filename = Str.global_replace (Str.regexp "\\$AC_ID") ac_id (ExtXml.attrib s "href") in
       let subxml = Xml.parse_file filename in
       printf "/* XML %s */" filename;
       nl ();