diff --git a/modules/clan/phonebox/default.nix b/modules/clan/phonebox/default.nix
index 9243f97..a9f1623 100644
--- a/modules/clan/phonebox/default.nix
+++ b/modules/clan/phonebox/default.nix
@@ -262,8 +262,8 @@
 
                   "rtp.conf" = ''
                     [general]
-                    rtpstart=${rtpPortFrom}
-                    rtpend=${rtpPortTo}
+                    rtpstart=${builtins.toString rtpPortFrom}
+                    rtpend=${builtins.toString rtpPortTo}
                   '';
 
                   "pjsip.conf" =
diff --git a/modules/clan/phonebox/flake-module.nix b/modules/clan/phonebox/flake-module.nix
index bfc0645..0b88413 100644
--- a/modules/clan/phonebox/flake-module.nix
+++ b/modules/clan/phonebox/flake-module.nix
@@ -1,7 +1,6 @@
 {
   inputs,
   self,
-  lib,
   ...
 }:
 let
@@ -12,7 +11,7 @@ in
     phonebox = module;
   };
   perSystem =
-    { hostPkgs, ... }:
+    { ... }:
     {
       clan.nixosTests.service-phonebox = {
         imports = [ ./tests/vm/default.nix ];