diff --git a/default.nix b/default.nix
index 48739fd..ebaa6b3 100644
--- a/default.nix
+++ b/default.nix
@@ -1,17 +1,17 @@
-{ lib, python312Packages, pkgs }:
-with python312Packages;
+{ lib, python313Packages, pkgs }:
+with python313Packages;
 let
   # Maintained fork of the original TTS package
   coqui-tts =
     let
       pname = "coqui_tts";
-      version = "0.26.2";
+      version = "0.27.2";
     in
     buildPythonPackage {
       inherit pname version;
       src = pkgs.fetchPypi {
         inherit pname version;
-        sha256 = "sha256-DSD5W3Pl82hH0RxO0Vnme/2fozZlRmBRMbmKMRboNjc=";
+        sha256 = "sha256-GBxcUf4sVxG0H54KHMvSaZZXI1vpJ3oEruwoWhihtpM=";
       };
       doCheck = false;
       pyproject = true;
@@ -21,6 +21,35 @@ let
 
       ];
 
+      postPatch =
+    let
+      relaxedConstraints = [
+        "bnunicodenormalizer"
+        "coqpit-config"
+        "cython"
+        "gruut"
+        "inflect"
+        "librosa"
+        "mecab-python3"
+        "numba"
+        "numpy"
+        "unidic-lite"
+        "trainer"
+        "spacy\\[ja\\]"
+        "transformers"
+        "torch"
+        "torchaudio"
+      ];
+    in
+    ''
+      sed -r -i \
+        ${lib.concatStringsSep "\n" (
+          map (package: ''-e 's/${package}\s*[<>=]+[^"]+/${package}/g' \'') relaxedConstraints
+        )}
+      pyproject.toml
+    '';
+
+
       nativeBuildInputs = [ pkgs.espeak-ng ];
 
       dependencies = [
diff --git a/flake.lock b/flake.lock
index 31b6737..462bbd2 100644
--- a/flake.lock
+++ b/flake.lock
@@ -2,16 +2,16 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1753749649,
-        "narHash": "sha256-+jkEZxs7bfOKfBIk430K+tK9IvXlwzqQQnppC2ZKFj4=",
+        "lastModified": 1765311797,
+        "narHash": "sha256-mSD5Ob7a+T2RNjvPvOA1dkJHGVrNVl8ZOrAwBjKBDQo=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "1f08a4df998e21f4e8be8fb6fbf61d11a1a5076a",
+        "rev": "09eb77e94fa25202af8f3e81ddc7353d9970ac1b",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-25.05",
+        "ref": "nixos-25.11",
         "repo": "nixpkgs",
         "type": "github"
       }
diff --git a/flake.nix b/flake.nix
index 73649cc..f3af1b1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,7 +1,7 @@
 {
   description = "A flake for the mensa-tts system.";
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
   };
 
 
diff --git a/src/mensa_to_speech.py b/src/mensa_to_speech.py
index 8d7476b..7592dee 100644
--- a/src/mensa_to_speech.py
+++ b/src/mensa_to_speech.py
@@ -67,7 +67,7 @@ DAYS = {
 
 
 START = (
-    "Achtung! Achtung! Meine Damen und Herren, D B 0 K L bittet um ihre Aufmerksamkeit!\n"
+    "Biep. Achtung! Achtung! Meine Damen und Herren, D B 0 K L bittet um ihre Aufmerksamkeit!\n"
     + "Es folgt der Mensaplan für heute, den "
 )