diff --git a/messages/de.json b/messages/de.json
index fc87db8..625a2ec 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -1,6 +1,11 @@
 {
 	"$schema": "https://inlang.com/schema/inlang-message-format",
-	"language": "Deutsch - German",
+	"language": {
+		"name": "Deutsch - German",
+		"tts": "de",
+		"speechSynthesis": "de-DE",
+		"valhalla": "de"
+	},
 	"saved": {
 		"home": "Heim",
 		"school": "Schule",
diff --git a/messages/en.json b/messages/en.json
index 377559a..85063b1 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -1,6 +1,11 @@
 {
 	"$schema": "https://inlang.com/schema/inlang-message-format",
-	"language": "English",
+	"language": {
+		"name": "English",
+		"tts": "en",
+		"speechSynthesis": "en-US",
+		"valhalla": "en"
+	},
 	"save": "Save",
 	"cancel": "Cancel",
 	"loading": "Loading...",
diff --git a/src/lib/components/lnv/sidebar/settings/LanguageSidebar.svelte b/src/lib/components/lnv/sidebar/settings/LanguageSidebar.svelte
index 9105264..c071975 100644
--- a/src/lib/components/lnv/sidebar/settings/LanguageSidebar.svelte
+++ b/src/lib/components/lnv/sidebar/settings/LanguageSidebar.svelte
@@ -13,10 +13,10 @@
 <div id="languages">
 	{#each locales as locale, _index (locale)}
 		{#if locale == getLocale()}
-			<SettingsButton text={m.language()} icon={CheckIcon} disabled />
+			<SettingsButton text={m["language.name"]()} icon={CheckIcon} disabled />
 		{:else}
 			<SettingsButton
-				text={m.language({}, { locale })}
+				text={m["language.name"]({}, { locale })}
 				icon={LanguagesIcon}
 				onclick={() => {
 					setLocale(locale);
diff --git a/src/lib/services/navigation/TTS.ts b/src/lib/services/navigation/TTS.ts
index 4ee9229..3a57cff 100644
--- a/src/lib/services/navigation/TTS.ts
+++ b/src/lib/services/navigation/TTS.ts
@@ -1,5 +1,6 @@
 import { duck, unduck } from "tauri-plugin-duck-api";
 import { invoke } from "@tauri-apps/api/core";
+import { m } from "$lang/messages";
 
 export let tts: "tauri" | "web" | null = null;
 
@@ -23,14 +24,14 @@ export default async function say(text: string) {
 	duck();
 	if (tts !== "web") {
 		try {
-			await invoke("plugin:tts|speak", { text });
+			await invoke("plugin:tts|speak", { text, lang: m["language.tts"]() });
 		} catch (e) {
 			console.error("Error speaking text", e);
 			alert(e);
 		}
 	} else {
 		const utterance = new SpeechSynthesisUtterance(text);
-		utterance.lang = "de-DE";
+		utterance.lang = m["language.speechSynthesis"]();
 		window.speechSynthesis.speak(utterance);
 	}
 	unduck();
diff --git a/src/lib/vehicles/ValhallaVehicles.ts b/src/lib/vehicles/ValhallaVehicles.ts
index 40cc2bc..e622304 100644
--- a/src/lib/vehicles/ValhallaVehicles.ts
+++ b/src/lib/vehicles/ValhallaVehicles.ts
@@ -1,3 +1,4 @@
+import { m } from "$lang/messages";
 import type {
 	ValhallaCosting,
 	ValhallaCostingOptions,
@@ -63,7 +64,7 @@ export function createValhallaRequest(
 		costing,
 		units: "kilometers",
 		alternates: 2,
-		language: "de-DE",
+		language: m["language.valhalla"](),
 		costing_options: costingOptions,
 		turn_lanes: true,
 	};