diff --git a/lib/paf_mirage.ml b/lib/paf_mirage.ml
index 02bd55f..b273d93 100644
--- a/lib/paf_mirage.ml
+++ b/lib/paf_mirage.ml
@@ -1,7 +1,11 @@
 module type S = sig
   type stack
 
-  module TCP : Mirage_flow.S
+  module TCP : sig
+    include Mirage_flow.S
+
+    val dst : flow -> Ipaddr.t * int
+  end
 
   module TLS : module type of Tls_mirage.Make (TCP)
 
diff --git a/lib/paf_mirage.mli b/lib/paf_mirage.mli
index be9719c..9b48cb7 100644
--- a/lib/paf_mirage.mli
+++ b/lib/paf_mirage.mli
@@ -2,7 +2,11 @@ module type S = sig
   type stack
   (** The type of the TCP/IP stack. *)
 
-  module TCP : Mirage_flow.S
+  module TCP : sig
+    include Mirage_flow.S
+
+    val dst : flow -> Ipaddr.t * int
+  end
 
   module TLS : module type of Tls_mirage.Make (TCP)