diff --git a/dist/runtime/composables/index.js b/dist/runtime/composables/index.js
index ca736eae7a45ab3752c3f408c971c06bccd4f91b..ec9d34c497249576b6eb00adf3c727960778bae4 100644
--- a/dist/runtime/composables/index.js
+++ b/dist/runtime/composables/index.js
@@ -4,7 +4,24 @@ import { runtimeDetectBrowserLanguage, wrapComposable } from "../internal.js";
 import { localeCodes } from "#build/i18n.options.mjs";
 import { _useLocaleHead, _useSetI18nParams } from "../routing/head.js";
 import { getRouteBaseName, localePath, localeRoute, switchLocalePath } from "../routing/routing.js";
-export * from "vue-i18n";
+// Re-export everything from vue-i18n EXCEPT useI18n
+// useI18n is replaced with a safe version that uses Nuxt's async-context-aware $i18n
+// to avoid Error 27 (NOT_INSTALLED) on Cloudflare Workers with concurrent SSR requests
+export { DatetimeFormat, I18nD, I18nInjectionKey, I18nN, I18nT, NumberFormat, Translation, VERSION, createI18n, vTDirective } from "vue-i18n";
+
+/**
+ * Safe useI18n replacement that uses Nuxt's $i18n instead of vue-i18n's useI18n.
+ *
+ * vue-i18n's useI18n() calls getCurrentInstance() which returns a module-level
+ * variable shared across concurrent Cloudflare Workers requests. This causes
+ * Error 27 when the instance from a different request's Vue app is returned.
+ *
+ * useNuxtApp() uses AsyncLocalStorage and is request-scoped, avoiding this issue.
+ */
+export function useI18n(options) {
+  const nuxtApp = useNuxtApp();
+  return nuxtApp.$i18n;
+}
 export * from "./shared.js";
 export function useSetI18nParams(seo) {
   return wrapComposable(_useSetI18nParams)(seo);
diff --git a/dist/runtime/plugins/i18n.js b/dist/runtime/plugins/i18n.js
index 7a71fcfda18c0770be2c4b7a0b3c2b875bbb832e..cd008b4126400a909bcc66897a1344cb5659e8a6 100644
--- a/dist/runtime/plugins/i18n.js
+++ b/dist/runtime/plugins/i18n.js
@@ -157,7 +157,9 @@ export default defineNuxtPlugin({
       }
     });
     nuxt.vueApp.use(i18n);
-    Object.defineProperty(nuxt, "$i18n", { get: () => getI18nTarget(i18n) });
+    if (!Object.prototype.hasOwnProperty.call(nuxt, '$i18n')) {
+      Object.defineProperty(nuxt, "$i18n", { get: () => getI18nTarget(i18n), configurable: true });
+    }
     return {
       provide: {
         /**