diff --git a/ocaml/Scheduler.ml b/ocaml/Scheduler.ml
index 7e9ae2d..3d30d3d 100644
--- a/ocaml/Scheduler.ml
+++ b/ocaml/Scheduler.ml
@@ -17,7 +17,7 @@ let find () =
   let scheduler = 
     [  "SLURM_NODELIST" ; "PE_HOSTFILE" ; "PBS_NODEFILE" ]
     |> List.map (function x -> 
-         try Some (Sys.getenv x) with
+         try ignore @@ (Sys.getenv x) ; Some x with
          | Not_found -> None
          )
     |> List.hd