diff --git a/lib-cudf/opam_0install_cudf.ml b/lib-cudf/opam_0install_cudf.ml
index 4ccaed8..c51bd3f 100644
--- a/lib-cudf/opam_0install_cudf.ml
+++ b/lib-cudf/opam_0install_cudf.ml
@@ -4,12 +4,20 @@ let tagged_with_avoid_version pkg =
     | _ -> false
   ) pkg.Cudf.pkg_extra
 
-let version_rev_compare ~prefer_oldest pkg1 pkg2 =
-  let rev cmp = if prefer_oldest then cmp else -cmp in
-  match tagged_with_avoid_version pkg1, tagged_with_avoid_version pkg2 with
-  | true, true | false, false -> rev (Int.compare pkg1.Cudf.version pkg2.Cudf.version)
-  | true, false -> 1
-  | false, true -> -1
+let version_rev_compare ~prefer_oldest =
+  (* Unrolled for performance purpose *)
+  if prefer_oldest then
+    fun pkg1 pkg2 ->
+      match tagged_with_avoid_version pkg1, tagged_with_avoid_version pkg2 with
+      | true, true | false, false -> Int.compare pkg1.Cudf.version pkg2.Cudf.version
+      | true, false -> 1
+      | false, true -> -1
+  else
+    fun pkg1 pkg2 ->
+      match tagged_with_avoid_version pkg1, tagged_with_avoid_version pkg2 with
+      | true, true | false, false -> Int.compare pkg2.Cudf.version pkg1.Cudf.version
+      | true, false -> 1
+      | false, true -> -1
 
 module Context = struct
   type rejection = UserConstraint of Cudf_types.vpkg