diff --git a/src/data.ts b/src/data.ts
new file mode 100644
index 0000000..182eadf
--- /dev/null
+++ b/src/data.ts
@@ -0,0 +1,82 @@
+export const locales = {
+  Afrikaans: "Hallo, wêreld!",
+  Albanian: "Pershëndetje Botë",
+  Arabic: "أهلاً بالعالم (Ahlan bil 'Alam)",
+  Armenian: "Բարե՛ւ, աշխարհ։ (barev ash'kharh)",
+  Azeri: "Salam Dünya",
+  Czech: "Ahoj Světe!",
+  BasqueEuskara: "Kaixo mundua!",
+  Belarusian: "Прывітанне свет	(Pryvitannie sviet)",
+  Bemba: "Shani Mwechalo!",
+  Bengali: "Shagatam Prithivi!",
+  Bosnian: "Zdravo Svijete!",
+  Bulgarian: "Здравей, свят! (Zdrav'ei svi'at)",
+  Cambodian: "ជំរាបសួរ ពិភពលោក	(chomreabsuor piphoplok)",
+  Catalan: "Hola món!",
+  Chinese: "你好世界 (nǐ hǎo shì jiè)",
+  Cherokee: "ᎣᏏᏲ ᎡᎶᎯ (O-si-yo E-lo-hi)",
+  ChinookWawa: "Klahowya Hayas Klaska",
+  Croatian: "Bok Svijete!",
+  Danish: "Hej, Verden!",
+  Dutch: "Hallo, wereld!",
+  English: "Hello World!",
+  Esperanto: "Saluton mondo!",
+  Estonian: "Tere maailm!",
+  Finnish: "Hei maailma!",
+  French: "Salut le Monde!",
+  Frisian: "Hallo, wrâld!",
+  Galician: "Ola mundo!",
+  German: "Hallo Welt!",
+  Greek: "Γεια σου κόσμε!	(Geia soy kosme)",
+  Hawaiian: "Aloha Honua",
+  Hebrew: "Shalom Olam",
+  Hindi: "नमस्ते दुनिया	(namaste duniya)",
+  Hmong: "Nyob zoo ntiaj teb.",
+  Hungarian: "Helló világ!",
+  Icelandic: "Halló heimur!",
+  Igbo: "Ndewo Ụwa",
+  Indonesian: "Halo Dunia!",
+  Irish: "Dia dhaoibh, a dhomhain!",
+  Italian: "Ciao Mondo!",
+  Japanese: "こんにちは、 世界！	(konnichiwa sekai)",
+  Kannada: "ಹಲೋ ವರ್ಲ್ಡ್	(Halō varlḍ)",
+  Kiswahili: "Habari dunia!",
+  Kikuyu: "Niatia thi!",
+  Klingon: "nuqneH",
+  Korean: "반갑다 세상아	(bangabda, sesangah)",
+  Lao: "ສະບາຍດີ,ໂລກ	(sabaidi olk)",
+  Latin: "AVE MVNDE	(ave munde)",
+  Latvian: "Sveika, Pasaule!",
+  Lithuanian: "Sveikas, Pasauli",
+  Lojban: "coi li terdi",
+  Luxembourgish: "Moien Welt!",
+  Malagasy: "Manao ahoana ry tany!",
+  Malayalam: "Namaskaram, lokame",
+  Maltese: "Merhba lid-dinja",
+  Norwegian: "Hallo verden!",
+  Persian: "!سلام دنیا	(Salaam Donyaa!)",
+  Polish: "Witaj świecie!",
+  Portuguese: "Olá, mundo!",
+  Punjabi: "ਸਤਿ ਸ੍ਰੀ ਅਕਾਲ ਦੁਨਿਆ	(Sati srī akāla duni'ā)",
+  Romanian: "Salut lume!",
+  Russian: "Здравствуй, мир!	(Zdra'vstvuj mi'r)",
+  Scots: "Gaelic	Halò, a Shaoghail!",
+  Serbian: "Zdravo Svete!",
+  Slovak: "Ahoj, svet!",
+  Slovenian: "Pozdravljen svet!",
+  Spanish: "¡Hola mundo!",
+  Swedish: "Hallå världen!",
+  Tagalog: "Kamusta mundo!",
+  Tamil: "ஹலோ உலகம்	(Halō ulakam)",
+  Telugu: "హలో వరల్డ్	(Halō varalḍ)",
+  Thai: "สวัสดีโลก!	(sawadee lok)",
+  Turkish: "Merhaba Dünya!",
+  Ukrainian: "Привiт, свiте!	(Pryvi't svi'te)",
+  Urdu: "ہیلو دنیا والو",
+  Vietnamese: "Xin chào thế giới",
+  Welsh: "S'mae byd!",
+  Yiddish: "העלא וועלט	(hela velt)",
+  Zulu: "Sawubona Mhlaba",
+};
+
+export const localesSize = Object.keys(locales).length;
diff --git a/src/index.test.ts b/src/index.test.ts
index 5816e06..2e81467 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -4,6 +4,7 @@ import {
 } from "https://deno.land/std@0.87.0/testing/asserts.ts";
 import { sayHello } from "./index.ts";
 import { ValidationError } from "./validation.ts";
+import { localesSize } from "./data.ts";
 
 Deno.test("Hello test", () => {
   const actual = sayHello();
@@ -25,6 +26,10 @@ Deno.test("Hello fails for non strictly positive values", () => {
 });
 
 Deno.test("Hello fails for too large values", () => {
-  const id = 666;
-  assertThrows(() => sayHello(id), ValidationError, "Invalid index: 666");
+  const id = localesSize;
+  assertThrows(
+    () => sayHello(id),
+    ValidationError,
+    `Invalid index: ${localesSize}`,
+  );
 });
diff --git a/src/index.ts b/src/index.ts
index 9cfe9ce..e81bc88 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,5 @@
 import { ValidationError } from "./validation.ts";
+import { localesSize } from "./data.ts";
 
 /**
  * Display the iconic Hello, World
@@ -10,4 +11,4 @@ export const sayHello = (id?: number) => {
   return (id === 5) ? "Bonjour le monde" : "Hello, World!";
 };
 
-const idInValidRange = (id: number) => id < 1 || id > 100;
+const idInValidRange = (id: number) => id < 1 || id >= localesSize;