diff --git a/compile.ml b/compile.ml
index 7450687..408bbbb 100644
--- a/compile.ml
+++ b/compile.ml
@@ -12,6 +12,16 @@ module Prefix = struct
     | Not a, Not b -> -compare a b
     | Not _, _ -> -1
     | _, Not _ -> 1
+
+  let rec to_ipv4_list negate = function
+    | Ipv4 ipv4 -> if negate then [] else [ ipv4 ]
+    | Ipv6 _ -> []
+    | Not prefix -> to_ipv4_list (not negate) prefix
+
+  let rec to_ipv6_list negate = function
+    | Ipv4 _ -> []
+    | Ipv6 ipv6 -> if negate then [] else [ ipv6 ]
+    | Not prefix -> to_ipv6_list (not negate) prefix
 end
 
 module PrefixSet = struct
@@ -31,75 +41,89 @@ module PrefixSet = struct
     List.fold_left (fun acc addrs -> union (of_addrs zone addrs) acc) empty
 end
 
-let rec zone_deps =
-  let open Config.Zone in
-  function
-  | Ipv4 _ | Ipv6 _ -> []
-  | Name name -> [ name ]
-  | List list -> List.flatten (List.map zone_deps list)
-  | Not not -> zone_deps not
-
-let zones_deps zone = List.map (fun (k, v) -> (k, zone_deps v)) zone
-
-let rec compile_zone assoc =
-  let open Config.Zone in
-  function
-  | Ipv4 ipv4 -> PrefixSet.singleton (Prefix.Ipv4 ipv4)
-  | Ipv6 ipv6 -> PrefixSet.singleton (Prefix.Ipv6 ipv6)
-  | Name name -> List.assoc name assoc
-  | List list ->
-      List.fold_left
-        (fun acc zone -> PrefixSet.union (compile_zone assoc zone) acc)
-        PrefixSet.empty list
-  | Not zone -> PrefixSet.map (fun p -> Prefix.Not p) (compile_zone assoc zone)
-
-let compile_zones zones =
-  match Tsort.sort (zones_deps zones) with
-  | Tsort.Sorted sorted ->
-      List.fold_right
-        (fun name acc ->
-          let zone = List.assoc name zones in
-          let compiled = compile_zone acc zone in
-          (name, compiled) :: acc)
-        sorted []
-  | _ -> failwith "cyclic dependency in zones definitions"
-
-let find_ipv4 zones negate addrs_list =
-  let open Prefix in
-  let prefixes = PrefixSet.of_addrs_list zones addrs_list in
-  let rec filter_prefix negate prefix acc =
-    match prefix with
-    | Ipv4 ipv4 -> if negate then acc else ipv4 :: acc
-    | Ipv6 _ -> acc
-    | Not prefix -> filter_prefix (not negate) prefix acc
-  in
-  PrefixSet.fold (filter_prefix negate) prefixes []
+module Zones = struct
+  open Config.Zone
 
-let compile_addrs_ipv4 zones field addrs =
-  let open Nftables in
-  let equal = find_ipv4 zones false addrs |> List.map (fun p -> Expr.Ipv4 p) in
-  let not_equal =
-    find_ipv4 zones true addrs |> List.map (fun p -> Expr.Ipv4 p)
-  in
-  (* TODO: handle empty sets *)
-  [
-    Stmt.Match (Match.Eq, Expr.Payload (Payload.Ipv4 field), Expr.Set equal);
-    Stmt.Match
-      (Match.NotEq, Expr.Payload (Payload.Ipv4 field), Expr.Set not_equal);
-  ]
-
-let compile_rule zones rule =
-  let open Config.Rule in
-  let open Nftables in
-  let ipv4_src = compile_addrs_ipv4 zones Payload.Ipv4.Saddr rule.src in
-  let ipv4_dest = compile_addrs_ipv4 zones Payload.Ipv4.Daddr rule.dest in
-  List.flatten [ ipv4_src; ipv4_dest ]
+  let dependencies zone =
+    let rec aux = function
+      | Ipv4 _ | Ipv6 _ -> []
+      | Name name -> [ name ]
+      | List list -> List.flatten (List.map aux list)
+      | Not not -> aux not
+    in
+    List.map (fun (k, v) -> (k, aux v)) zone
+
+  let rec compile_zone assoc = function
+    | Ipv4 ipv4 -> PrefixSet.singleton (Prefix.Ipv4 ipv4)
+    | Ipv6 ipv6 -> PrefixSet.singleton (Prefix.Ipv6 ipv6)
+    | Name name -> List.assoc name assoc
+    | List list ->
+        List.fold_left
+          (fun acc zone -> PrefixSet.union (compile_zone assoc zone) acc)
+          PrefixSet.empty list
+    | Not zone ->
+        PrefixSet.map (fun p -> Prefix.Not p) (compile_zone assoc zone)
+
+  let compile zones =
+    match Tsort.sort (dependencies zones) with
+    | Tsort.Sorted sorted ->
+        List.fold_right
+          (fun name acc ->
+            let zone = List.assoc name zones in
+            let compiled = compile_zone acc zone in
+            (name, compiled) :: acc)
+          sorted []
+    | _ -> failwith "cyclic dependency in zones definitions"
+end
+
+module Rules = struct
+  open Nftables
+  open Config.Rule
+
+  (* Bon, ce module n'est vraiment pas très joli… *)
+
+  let compile_addrs_list getter expr negate zones addrs_list =
+    Expr.Set
+      (PrefixSet.fold
+         (fun prefix acc -> getter negate prefix @ acc)
+         (PrefixSet.of_addrs_list zones addrs_list)
+         []
+      |> List.map expr)
+
+  let compile_match_addrs getter expr field zones addrs_list =
+    [
+      Stmt.Match
+        ( Match.Eq,
+          Expr.Payload field,
+          compile_addrs_list getter expr false zones addrs_list );
+      Stmt.Match
+        ( Match.NotEq,
+          Expr.Payload field,
+          compile_addrs_list getter expr true zones addrs_list );
+    ]
+
+  let compile_match_ipv4 field =
+    compile_match_addrs Prefix.to_ipv4_list Expr.ipv4 (Payload.Ipv4 field)
+
+  let compile_match_ipv6 field =
+    compile_match_addrs Prefix.to_ipv6_list Expr.ipv6 (Payload.Ipv6 field)
+
+  let compile_rule zones { src; dest; _ } =
+    let ipv4_src = compile_match_ipv4 Payload.Ipv4.Saddr zones src in
+    let ipv4_dest = compile_match_ipv4 Payload.Ipv4.Daddr zones dest in
+    let ipv6_src = compile_match_ipv6 Payload.Ipv6.Saddr zones src in
+    let ipv6_dest = compile_match_ipv6 Payload.Ipv6.Daddr zones dest in
+    let verdict = [ Stmt.Verdict Verdict.Accept ] in
+    [ ipv4_src @ ipv4_dest @ verdict; ipv6_src @ ipv6_dest @ verdict ]
+
+  let compile zones rules = List.flatten (List.map (compile_rule zones) rules)
+end
 
 let compile config =
   let open Nftables in
   let open Config in
-  let zones = compile_zones config.zones in
-  let exprs = List.map (compile_rule zones) config.rules in
+  let zones = Zones.compile config.zones in
+  let exprs = Rules.compile zones config.rules in
   let family = Family.Inet in
   let table = "filter" in
   let chain = "forward" in