diff --git a/src/indexOptions.ml b/src/indexOptions.ml
index 0669790..b03be72 100644
--- a/src/indexOptions.ml
+++ b/src/indexOptions.ml
@@ -46,9 +46,11 @@ let filter opt info =
   | ModuleType | ClassType -> kinds.s
   | Keyword -> kinds.k
 
+let null_file = if Sys.win32 then "NUL" else "/dev/null"
+
 let cmd_input_line cmd =
   try
-    let ic = Unix.open_process_in (cmd ^ " 2>/dev/null") in
+    let ic = Unix.open_process_in (Printf.sprintf "%s 2>%s" cmd null_file) in
     let r = input_line ic in
     let r =
       let len = String.length r in
@@ -72,6 +74,15 @@ let filter_to_string l =
   in
   String.concat "," (List.map pp l)
 
+let initial_cwd = Sys.getcwd ()
+
+let path_sep = if Sys.win32 then ';' else ':'
+
+let parse_path_var s =
+  let l = String.split_on_char path_sep s in
+  let l = List.filter (fun s -> s <> "") l in
+  List.map (fun path -> if Filename.is_relative path then Filename.concat initial_cwd path else path) l
+
 let common_opts ?(default_filter = default_filter) () : t Term.t =
   let ocamllib : string list Term.t =
     let no_stdlib : bool Term.t =
@@ -90,6 +101,11 @@ let common_opts ?(default_filter = default_filter) () : t Term.t =
     in
     let set_default no_stdlib no_opamlib includes =
       let paths = List.flatten includes in
+      let paths =
+        match Sys.getenv "OCAMLPATH" with
+        | exception Not_found -> paths
+        | s -> parse_path_var s @ paths
+      in
       let paths =
         if no_opamlib then paths else
           try cmd_input_line "opam config var lib" :: paths