--- a/netwerk/cache2/CacheFileIOManager.cpp
+++ b/netwerk/cache2/CacheFileIOManager.cpp
@@ -1293,16 +1293,21 @@ CacheFileIOManager::ShutdownInternal()
 {
   LOG(("CacheFileIOManager::ShutdownInternal() [this=%p]", this));
 
   MOZ_ASSERT(mIOThread->IsCurrentThread());
 
   // No new handles can be created after this flag is set
   mShuttingDown = true;
 
+  if (mTrashTimer) {
+    mTrashTimer->Cancel();
+    mTrashTimer = nullptr;
+  }
+
   // close all handles and delete all associated files
   nsTArray<RefPtr<CacheFileHandle> > handles;
   mHandles.GetAllHandles(&handles);
   handles.AppendElements(mSpecialHandles);
 
   for (uint32_t i=0 ; i<handles.Length() ; i++) {
     CacheFileHandle *h = handles[i];
     h->mClosed = true;

--- a/netwerk/cache2/CacheIndex.cpp
+++ b/netwerk/cache2/CacheIndex.cpp
@@ -393,16 +393,17 @@ CacheIndex::PreShutdownInternal()
 
   LOG(("CacheIndex::PreShutdownInternal() - [state=%d, indexOnDiskIsValid=%d, "
        "dontMarkIndexClean=%d]", mState, mIndexOnDiskIsValid,
        mDontMarkIndexClean));
 
   MOZ_ASSERT(mShuttingDown);
 
   if (mUpdateTimer) {
+    mUpdateTimer->Cancel();
     mUpdateTimer = nullptr;
   }
 
   switch (mState) {
     case WRITING:
       FinishWrite(false);
       break;
     case READY: