diff --git a/intl/strres/nsStringBundle.cpp b/intl/strres/nsStringBundle.cpp
--- a/intl/strres/nsStringBundle.cpp
+++ b/intl/strres/nsStringBundle.cpp
@@ -753,10 +753,11 @@
                                const char16_t* aSomeData) {
   if (strcmp("profile-do-change", aTopic) == 0 ||
       strcmp("chrome-flush-caches", aTopic) == 0 ||
       strcmp("intl:app-locales-changed", aTopic) == 0) {
     flushBundleCache(/* ignoreShared = */ false);
+    mBundleMap.Clear();
   } else if (strcmp("memory-pressure", aTopic) == 0) {
     flushBundleCache(/* ignoreShared = */ true);
   }
 
   return NS_OK;