--- a/netwerk/cache2/CacheStorageService.cpp
+++ b/netwerk/cache2/CacheStorageService.cpp
@@ -141,37 +141,43 @@ void CacheStorageService::Shutdown()
   LOG(("CacheStorageService::Shutdown - start"));
 
   mShutdown = true;
 
   nsCOMPtr<nsIRunnable> event =
     NewRunnableMethod(this, &CacheStorageService::ShutdownBackground);
   Dispatch(event);
 
-  mozilla::MutexAutoLock lock(mLock);
-  sGlobalEntryTables->Clear();
-  delete sGlobalEntryTables;
-  sGlobalEntryTables = nullptr;
+  {
+    mozilla::MutexAutoLock lock(mLock);
+#ifdef NS_FREE_PERMANENT_DATA
+    sGlobalEntryTables->Clear();
+    delete sGlobalEntryTables;
+#endif
+    sGlobalEntryTables = nullptr;
+  }
 
   LOG(("CacheStorageService::Shutdown - done"));
 }
 
 void CacheStorageService::ShutdownBackground()
 {
   MOZ_ASSERT(IsOnManagementThread());
 
   // Cancel purge timer to avoid leaking.
   if (mPurgeTimer) {
     mPurgeTimer->Cancel();
   }
 
+#ifdef NS_FREE_PERMANENT_DATA
   Pool(false).mFrecencyArray.Clear();
   Pool(false).mExpirationArray.Clear();
   Pool(true).mFrecencyArray.Clear();
   Pool(true).mExpirationArray.Clear();
+#endif
 }
 
 // Internal management methods
 
 namespace {
 
 // WalkCacheRunnable
 // Base class for particular storage entries visiting