diff --git a/nixos/doc/manual/release-notes/rl-2511.section.md b/nixos/doc/manual/release-notes/rl-2511.section.md
index fa08bb988f7e..83b52f4f73b6 100644
--- a/nixos/doc/manual/release-notes/rl-2511.section.md
+++ b/nixos/doc/manual/release-notes/rl-2511.section.md
@@ -36,6 +36,8 @@
 
 - The Pocket ID module ([`services.pocket-id`][#opt-services.pocket-id.enable]) and package (`pocket-id`) has been updated to 1.0.0. Some environment variables have been changed or removed, see the [migration guide](https://pocket-id.org/docs/setup/migrate-to-v1/).
 
+- The `services.siproxd` module has been removed as `siproxd` is unmaintained and broken with libosip 5.x.
+
 - `renovate` was updated to v40. See the [upstream release notes](https://github.com/renovatebot/renovate/releases/tag/40.0.0) for breaking changes.
 
 ## Other Notable Changes {#sec-release-25.11-notable-changes}
diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index 34419e33f3f3..29c23ae1bac9 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -909,7 +909,6 @@
   ./services/misc/servarr/whisparr.nix
   ./services/misc/serviio.nix
   ./services/misc/sickbeard.nix
-  ./services/misc/siproxd.nix
   ./services/misc/snapper.nix
   ./services/misc/soft-serve.nix
   ./services/misc/sourcehut
diff --git a/nixos/modules/rename.nix b/nixos/modules/rename.nix
index c75ee41099f4..a9fae629861d 100644
--- a/nixos/modules/rename.nix
+++ b/nixos/modules/rename.nix
@@ -223,6 +223,11 @@ in
       "services"
       "shout"
     ] "shout was removed because it was deprecated upstream in favor of thelounge.")
+    (mkRemovedOptionModule [ "services" "siproxd" ] ''
+      The siproxd package and the corresponding module have been removed due to
+      the service being unmaintained. `services.asterisk.*` or `services.freeswitch.*`
+      could be used instead.
+    '')
     (mkRemovedOptionModule [ "services" "ssmtp" ] ''
       The ssmtp package and the corresponding module have been removed due to
       the program being unmaintained. The options `programs.msmtp.*` can be
diff --git a/nixos/modules/services/misc/siproxd.nix b/nixos/modules/services/misc/siproxd.nix
deleted file mode 100644
index 822fc7b8d480..000000000000
--- a/nixos/modules/services/misc/siproxd.nix
+++ /dev/null
@@ -1,196 +0,0 @@
-{
-  config,
-  lib,
-  pkgs,
-  ...
-}:
-let
-
-  cfg = config.services.siproxd;
-
-  conf = ''
-    daemonize = 0
-    rtp_proxy_enable = 1
-    user = siproxd
-    if_inbound  = ${cfg.ifInbound}
-    if_outbound = ${cfg.ifOutbound}
-    sip_listen_port = ${toString cfg.sipListenPort}
-    rtp_port_low    = ${toString cfg.rtpPortLow}
-    rtp_port_high   = ${toString cfg.rtpPortHigh}
-    rtp_dscp        = ${toString cfg.rtpDscp}
-    sip_dscp        = ${toString cfg.sipDscp}
-    ${lib.optionalString (
-      cfg.hostsAllowReg != [ ]
-    ) "hosts_allow_reg = ${lib.concatStringsSep "," cfg.hostsAllowReg}"}
-    ${lib.optionalString (
-      cfg.hostsAllowSip != [ ]
-    ) "hosts_allow_sip = ${lib.concatStringsSep "," cfg.hostsAllowSip}"}
-    ${lib.optionalString (
-      cfg.hostsDenySip != [ ]
-    ) "hosts_deny_sip  = ${lib.concatStringsSep "," cfg.hostsDenySip}"}
-    ${lib.optionalString (cfg.passwordFile != "") "proxy_auth_pwfile = ${cfg.passwordFile}"}
-    ${cfg.extraConfig}
-  '';
-
-  confFile = builtins.toFile "siproxd.conf" conf;
-
-in
-{
-  ##### interface
-
-  options = {
-
-    services.siproxd = {
-
-      enable = lib.mkOption {
-        type = lib.types.bool;
-        default = false;
-        description = ''
-          Whether to enable the Siproxd SIP
-          proxy/masquerading daemon.
-        '';
-      };
-
-      ifInbound = lib.mkOption {
-        type = lib.types.str;
-        example = "eth0";
-        description = "Local network interface";
-      };
-
-      ifOutbound = lib.mkOption {
-        type = lib.types.str;
-        example = "ppp0";
-        description = "Public network interface";
-      };
-
-      hostsAllowReg = lib.mkOption {
-        type = lib.types.listOf lib.types.str;
-        default = [ ];
-        example = [
-          "192.168.1.0/24"
-          "192.168.2.0/24"
-        ];
-        description = ''
-          Access control list for incoming SIP registrations.
-        '';
-      };
-
-      hostsAllowSip = lib.mkOption {
-        type = lib.types.listOf lib.types.str;
-        default = [ ];
-        example = [
-          "123.45.0.0/16"
-          "123.46.0.0/16"
-        ];
-        description = ''
-          Access control list for incoming SIP traffic.
-        '';
-      };
-
-      hostsDenySip = lib.mkOption {
-        type = lib.types.listOf lib.types.str;
-        default = [ ];
-        example = [
-          "10.0.0.0/8"
-          "11.0.0.0/8"
-        ];
-        description = ''
-          Access control list for denying incoming
-          SIP registrations and traffic.
-        '';
-      };
-
-      sipListenPort = lib.mkOption {
-        type = lib.types.int;
-        default = 5060;
-        description = ''
-          Port to listen for incoming SIP messages.
-        '';
-      };
-
-      rtpPortLow = lib.mkOption {
-        type = lib.types.int;
-        default = 7070;
-        description = ''
-          Bottom of UDP port range for incoming and outgoing RTP traffic
-        '';
-      };
-
-      rtpPortHigh = lib.mkOption {
-        type = lib.types.int;
-        default = 7089;
-        description = ''
-          Top of UDP port range for incoming and outgoing RTP traffic
-        '';
-      };
-
-      rtpTimeout = lib.mkOption {
-        type = lib.types.int;
-        default = 300;
-        description = ''
-          Timeout for an RTP stream. If for the specified
-          number of seconds no data is relayed on an active
-          stream, it is considered dead and will be killed.
-        '';
-      };
-
-      rtpDscp = lib.mkOption {
-        type = lib.types.int;
-        default = 46;
-        description = ''
-          DSCP (differentiated services) value to be assigned
-          to RTP packets. Allows QOS aware routers to handle
-          different types traffic with different priorities.
-        '';
-      };
-
-      sipDscp = lib.mkOption {
-        type = lib.types.int;
-        default = 0;
-        description = ''
-          DSCP (differentiated services) value to be assigned
-          to SIP packets. Allows QOS aware routers to handle
-          different types traffic with different priorities.
-        '';
-      };
-
-      passwordFile = lib.mkOption {
-        type = lib.types.str;
-        default = "";
-        description = ''
-          Path to per-user password file.
-        '';
-      };
-
-      extraConfig = lib.mkOption {
-        type = lib.types.lines;
-        default = "";
-        description = ''
-          Extra configuration to add to siproxd configuration.
-        '';
-      };
-
-    };
-
-  };
-
-  ##### implementation
-
-  config = lib.mkIf cfg.enable {
-
-    users.users.siproxyd = {
-      uid = config.ids.uids.siproxd;
-    };
-
-    systemd.services.siproxd = {
-      description = "SIP proxy/masquerading daemon";
-      wantedBy = [ "multi-user.target" ];
-      after = [ "network.target" ];
-      serviceConfig = {
-        ExecStart = "${pkgs.siproxd}/sbin/siproxd -c ${confFile}";
-      };
-    };
-
-  };
-
-}