diff --git a/machines/rigel/configuration.nix b/machines/rigel/configuration.nix
index b820028..ce05492 100644
--- a/machines/rigel/configuration.nix
+++ b/machines/rigel/configuration.nix
@@ -1,4 +1,9 @@
-{ config, ... }:
+{
+  config,
+  pkgs,
+  self,
+  ...
+}:
 {
   imports = [
     (import ../../lib/auto-accept-zerotier-members.nix {
@@ -10,6 +15,8 @@
     })
   ];
 
+  nixpkgs.overlays = [ self.overlays.packagesOverlay ];
+
   system.stateVersion = "25.11";
   clan.core.sops.defaultGroups = [ "admins" ];
   clan.core.networking.targetHost = "root@[${config.clan.core.vars.generators.zerotier.files.zerotier-ip.value}]";
diff --git a/modules/clan/phonebox/default.nix b/modules/clan/phonebox/default.nix
index 446fc39..d5cdaa2 100644
--- a/modules/clan/phonebox/default.nix
+++ b/modules/clan/phonebox/default.nix
@@ -27,10 +27,12 @@
             lib,
             config,
             pkgs,
+            self,
             ...
           }:
           let
             user = "asterisk";
+            faxDir = "/run/asterisk/fax";
             rtpPortFrom = 10000;
             rtpPortTo = 20000;
             ata-interface = settings.ata-ethernet-iface;
@@ -240,6 +242,13 @@
                     syslog.local0 => notice,warning,error
                   '';
 
+                  "modules.conf" = ''
+                    [modules]
+                    autoload=yes
+
+                    load => res_fax_spandsp.so
+                  '';
+
                   # Dial plan config
                   "extensions.conf" =
                     let
@@ -257,6 +266,16 @@
                       same  =>     n,Playback(hello-world)
                       same  =>     n,Hangup()
 
+                      exten => 000,1,Answer()
+                      same => n,ReceiveFAX(${faxDir}/echo-''${UNIQUEID}.tiff)
+                      same => n,Set(FAXFILE=${faxDir}/echo-''${UNIQUEID}.tiff)
+                      same => n,Set(FAXECHO=true)
+
+                      exten => h,1,GotoIf($[''${FAXECHO}]?sendfax)
+                      same => n,Hangup()
+                      same => n(sendfax),Originate(PJSIP/00,app,SendFAX,${faxDir}/echo-''${UNIQUEID}.tiff)
+                      same => n,Set(FAXECHO=false)
+
                     ''
                     + (genLocalExtenConf {
                       localNumber = config.clan.core.vars.generators.phonebox.files.ata-local-number.value;
@@ -318,6 +337,10 @@
                 };
             };
 
+            systemd.tmpfiles.rules = [
+              "d ${faxDir}                            0755 ${user} ${user} - -"
+            ];
+
             systemd.services.asterisk-watcher = {
               enable = true;
               description = "Asterisk Configuration files watcher";
diff --git a/overlays/default.nix b/overlays/default.nix
index 583c8e9..6cdc1b2 100644
--- a/overlays/default.nix
+++ b/overlays/default.nix
@@ -2,5 +2,11 @@
 {
   flake.overlays = {
     packagesOverlay = import ../pkgs/overlay.nix;
+    asteriskOverlay = final: prev: {
+
+  asterisk = prev.asterisk.overrideAttrs (old: {
+    propagatedNativeBuildInputs = [ prev.pkgs.spandsp3 ];
+  });
+}
   };
 }