--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -1743,16 +1743,20 @@ var BrowserApp = {
 
       case "Locale:Changed": {
         if (data) {
           Services.locale.setRequestedLocales([data.languageTag]);
         } else {
           Services.locale.setRequestedLocales([]);
         }
 
+        // Blow away the string cache so that future lookups get the
+        // correct locale.
+        Strings.flush();
+
         // Make sure we use the right Accept-Language header.
         let osLocale;
         try {
           // This should never not be set at this point, but better safe than sorry.
           osLocale = Services.prefs.getCharPref("intl.locale.os");
         } catch (e) {
         }