diff --git a/sw/lib/ocaml/env.ml b/sw/lib/ocaml/env.ml
index 3fd89a95b7..abde93b67a 100644
--- a/sw/lib/ocaml/env.ml
+++ b/sw/lib/ocaml/env.ml
@@ -24,6 +24,8 @@
  *
  *)
 
+let (//) = Filename.concat
+
 let paparazzi_src =
   try
     Sys.getenv "PAPARAZZI_SRC"
@@ -35,3 +37,8 @@ let paparazzi_home =
     Sys.getenv "PAPARAZZI_HOME"
   with
     _ -> Filename.concat (Sys.getenv "HOME") "paparazzi"
+
+
+let flight_plans_path = paparazzi_home // "conf" // "flight_plans"
+
+let flight_plan_dtd = flight_plans_path // "flight_plan.dtd"
diff --git a/sw/lib/ocaml/env.mli b/sw/lib/ocaml/env.mli
index 76fc5e1eb2..692ddfbe48 100644
--- a/sw/lib/ocaml/env.mli
+++ b/sw/lib/ocaml/env.mli
@@ -29,3 +29,6 @@ val paparazzi_home : string
 
 val paparazzi_src : string
 (** Installation's files directory *)
+
+val flight_plans_path : string
+val flight_plan_dtd : string