diff --git a/src/ez_opam_file/dune b/src/ez_opam_file/dune
index 2d4f448..8430268 100644
--- a/src/ez_opam_file/dune
+++ b/src/ez_opam_file/dune
@@ -1,35 +1,11 @@
-(* -*- tuareg -*- *)
-
-let () =
-  let version = ref "new" in
-  let dir = Sys.getenv "OPAM_SWITCH_PREFIX" in
-  let packages_dir = dir ^ "/.opam-switch/packages" in
-  let packages = Sys.readdir packages_dir in
-  Array.iter (fun package ->
-    try
-       let pos = String.index package '.' in
-       let name = String.sub package 0 pos in
-       let vers = String.sub package
-          (pos+1) (String.length package - pos - 1) in
-       if name = "opam-file-format" && vers < "2.1.1" then version := "old"
-    with _ ->
-      Printf.eprintf "package %s\n%!" package
- ) packages;
-
- let version = !version in
-  Printf.kprintf
-    Jbuild_plugin.V1.send
-{|
 (library
   (name ez_opam_file)
   (public_name ez_opam_file)
   (wrapped true)
   (libraries opam-file-format
-    (select v1.ml from ( -> v1.%s.ml))
+    (select v1.ml from ( -> v1.new.ml))
     )
   )
 
 (documentation
   (package ez_opam_file))
-|}
-version