diff --git a/library/i18n/index.js b/library/i18n/index.js
index d1a79813d..20e4131e8 100644
--- a/library/i18n/index.js
+++ b/library/i18n/index.js
@@ -123,12 +123,18 @@ export function loadLocale(i18n, code) {
       return okEarlier
     })
   }
+  // ★ NO PIN, NO FETCH (studio). The hash map is written by the build ONLY for locales it actually
+  // emitted, so its presence is the one reliable statement that a file is there to fetch. Without
+  // this guard the flag-OFF build still reaches the network: a bundle with no areas inlines nothing,
+  // so messages[c] is empty and the preload requests locales/<lc>.json on every non-English page —
+  // a 404 per reader, and fetched with no integrity because there was no hash to pass. Keying on the
+  // pin makes the flag-off build inert and the flag-on build fail closed to English.
+  if (!LOCALE_SRI[c]) return Promise.resolve(!!messages[c])
   const run = (async () => {
     try {
       if (!LOCALE_BASE) return false                     // base unknown: stay on English
       const url = new URL(`locales/${c}.json`, LOCALE_BASE).href
-      const init = LOCALE_SRI[c] ? { integrity: LOCALE_SRI[c] } : {}
-      const res = await fetch(url, init)
+      const res = await fetch(url, { integrity: LOCALE_SRI[c] })
       if (!res.ok) return false
       const tree = await res.json()
       if (!tree || typeof tree !== 'object') return false