diff --git a/src/i18n/resolver.test.ts b/src/i18n/resolver.test.ts
index 2c0fcf0f..8a48d657 100644
--- a/src/i18n/resolver.test.ts
+++ b/src/i18n/resolver.test.ts
@@ -31,12 +31,18 @@ describe("isLanguage", () => {
 });
 
 describe("resolveLocaleFromPath", () => {
-  it("extracts BCP-47 locale from the first path segment", () => {
+  it("extracts Angular country-language locale from the first path segment", () => {
     expect(resolveLocaleFromPath("/ru-ru/onlineboard")).toBe("ru-ru");
     expect(resolveLocaleFromPath("/en-en/onlineboard/flight/SU100")).toBe("en-en");
     expect(resolveLocaleFromPath("/de-de/schedule")).toBe("de-de");
   });
 
+  it("accepts mixed country-language URLs and resolves language from the second part", () => {
+    expect(resolveLocaleFromPath("/ru-en/onlineboard")).toBe("ru-en");
+    expect(resolveLocaleFromPath("/ru-de/schedule")).toBe("ru-de");
+    expect(resolveLocaleFromPath("/ad-fr/onlineboard")).toBe("ad-fr");
+  });
+
   it("auto-promotes a bare short language code to its BCP-47 cousin", () => {
     expect(resolveLocaleFromPath("/ru/onlineboard")).toBe("ru-ru");
     expect(resolveLocaleFromPath("/en/onlineboard/flight/SU100")).toBe("en-en");
@@ -47,6 +53,8 @@ describe("resolveLocaleFromPath", () => {
     expect(resolveLocaleFromPath("/onlineboard")).toBeNull();
     expect(resolveLocaleFromPath("/xx/onlineboard")).toBeNull();
     expect(resolveLocaleFromPath("/xx-xx/onlineboard")).toBeNull();
+    expect(resolveLocaleFromPath("/russia-en/onlineboard")).toBeNull();
+    expect(resolveLocaleFromPath("/ru-eng/onlineboard")).toBeNull();
     expect(resolveLocaleFromPath("/")).toBeNull();
     expect(resolveLocaleFromPath("")).toBeNull();
   });
@@ -58,7 +66,7 @@ describe("resolveLocaleFromPath", () => {
 });
 
 describe("stripLocaleFromPath", () => {
-  it("strips BCP-47 locale and returns the rest", () => {
+  it("strips Angular country-language locale and returns the rest", () => {
     expect(stripLocaleFromPath("/ru-ru/onlineboard")).toEqual({
       locale: "ru-ru",
       rest: "/onlineboard",
@@ -67,6 +75,10 @@ describe("stripLocaleFromPath", () => {
       locale: "en-en",
       rest: "/onlineboard/flight/SU100",
     });
+    expect(stripLocaleFromPath("/ru-en/onlineboard")).toEqual({
+      locale: "ru-en",
+      rest: "/onlineboard",
+    });
   });
 
   it("auto-promotes short codes when stripping", () => {
diff --git a/src/i18n/resolver.ts b/src/i18n/resolver.ts
index 498c06e0..3377dd81 100644
--- a/src/i18n/resolver.ts
+++ b/src/i18n/resolver.ts
@@ -2,25 +2,16 @@
  * Locale codes used in URLs vs the short language code used for i18n
  * file lookup, API path segment, and `Accept-Language` header.
  *
- * Mirrors Angular's `LocalizationService`: URL is BCP-47 (`/ru-ru/`,
- * `/en-en/`, `/zh-zh/`...), backend + translation files use the short
- * 2-letter language part only (`ru`, `en`, `zh`...). This split keeps
- * the customer's URL contract while reusing a single set of locale
+ * Mirrors Angular's `LocalizationService`: URL is `/{country}-{language}`
+ * (`/ru-ru/`, `/ru-en/`, `/ru-de/`...), while backend + translation files
+ * use the second 2-letter segment only (`ru`, `en`, `de`...). This split
+ * keeps the customer's URL contract while reusing a single set of locale
  * resources.
  */
 
 export type Language = "ru" | "en" | "es" | "fr" | "it" | "ja" | "ko" | "zh" | "de";
 
-export type LocaleCode =
-  | "ru-ru"
-  | "en-en"
-  | "es-es"
-  | "fr-fr"
-  | "it-it"
-  | "ja-ja"
-  | "ko-ko"
-  | "zh-zh"
-  | "de-de";
+export type LocaleCode = `${string}-${Language}`;
 
 export const LANGUAGES: readonly Language[] = [
   "ru", "en", "es", "fr", "it", "ja", "ko", "zh", "de",
@@ -34,13 +25,11 @@ export const DEFAULT_LOCALE_CODE: LocaleCode = "ru-ru";
 export const DEFAULT_LANGUAGE: Language = "ru";
 
 const languageSet: ReadonlySet<string> = new Set(LANGUAGES);
-const localeCodeSet: ReadonlySet<string> = new Set(LOCALE_CODES);
+const URL_LOCALE_PATTERN = /^([a-z]{2})-([a-z]{2})$/;
 
-// Angular's URL contract is `/{country}-{language}` where the two
-// halves repeat the same 2-letter language code (see
-// `ClientApp/src/app/shared/services/localization.service.ts` —
-// `Country = baseHref[1..3]`, `Language = baseHref[4..6]`). We mirror
-// that exact shape so the React MF remote shares Angular's URL surface.
+// `languageToLocale` returns the canonical same-language URL used for
+// generated links, while `normalizeLocaleParam` below also accepts Angular's
+// mixed country-language URLs such as `/ru-en`.
 const LANGUAGE_TO_LOCALE_CODE: Record<Language, LocaleCode> = {
   ru: "ru-ru",
   en: "en-en",
@@ -58,15 +47,16 @@ export function isLanguage(x: string): x is Language {
 }
 
 export function isLocaleCode(x: string): x is LocaleCode {
-  return localeCodeSet.has(x);
+  const match = URL_LOCALE_PATTERN.exec(x);
+  return match ? isLanguage(match[2] ?? "") : false;
 }
 
 /**
- * Extract the language part from a BCP-47 locale code.
- * `localeToLanguage("en-en")` → `"en"`.
+ * Extract the language part from an Angular URL locale code.
+ * `localeToLanguage("ru-en")` → `"en"`.
  */
 export function localeToLanguage(code: LocaleCode): Language {
-  return code.slice(0, 2) as Language;
+  return code.split("-")[1] as Language;
 }
 
 /**
@@ -79,10 +69,10 @@ export function languageToLocale(lang: Language): LocaleCode {
 }
 
 /**
- * Read the locale code from `:lang` URL params. Accepts both BCP-47
- * (`ru-ru`) and bare short codes (`ru`) — the short form is promoted
- * to its canonical BCP-47 cousin so legacy / direct API consumers
- * keep working during migration.
+ * Read the locale code from `:lang` URL params. Accepts Angular
+ * country-language URLs (`ru-en`) and bare short codes (`en`) — the short
+ * form is promoted to its canonical same-language URL (`en-en`) so legacy /
+ * direct API consumers keep working during migration.
  */
 export function normalizeLocaleParam(raw: string | undefined): LocaleCode | null {
   if (!raw) return null;
diff --git a/tests/e2e/smoke.spec.ts b/tests/e2e/smoke.spec.ts
index 064addd6..35870bed 100644
--- a/tests/e2e/smoke.spec.ts
+++ b/tests/e2e/smoke.spec.ts
@@ -50,6 +50,29 @@ test.describe("Smoke tests", () => {
     await expect(page.getByText("en-en", { exact: true })).toBeVisible();
   });
 
+  test("/ru-en/onlineboard uses English language with Russia country prefix", async ({
+    page,
+    consoleMessages,
+  }) => {
+    await page.goto("/ru-en/onlineboard?_preferredLanguage=en&_preferredLocale=ruh");
+    await page.waitForLoadState("domcontentloaded");
+
+    await expect(page).toHaveURL(/\/ru-en\/onlineboard/);
+    await expect(page.locator("h1")).toHaveText("Online Timetable", {
+      timeout: 10000,
+    });
+    await expect(page.getByTestId("standalone-header")).toContainText("Services", {
+      timeout: 15000,
+    });
+    await expect(page.getByTestId("standalone-header")).toContainText("EN", {
+      timeout: 15000,
+    });
+    await expect(page.locator('afl-component[data-component="Footer"]')).toContainText(
+      "Contact us",
+      { timeout: 15000 },
+    );
+  });
+
   test("/xx/smoke shows 404 or unknown locale message", async ({ page, consoleMessages }) => {
     await page.goto("/xx/smoke");
     await page.waitForLoadState("domcontentloaded");