diff --git a/fw_utils.ml b/fw_utils.ml
index 3d547af..ffb58dc 100644
--- a/fw_utils.ml
+++ b/fw_utils.ml
@@ -10,14 +10,6 @@ module IpMap = struct
     with Not_found -> None
 end
 
-module Int = struct
-  type t = int
-  let compare (a:t) (b:t) = compare a b
-end
-
-module IntSet = Set.Make(Int)
-module IntMap = Map.Make(Int)
-
 (** An Ethernet interface. *)
 class type interface = object
   method my_mac : Macaddr.t