--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -9106,16 +9106,26 @@ nsHttpChannel::TriggerNetwork(int32_t aT
 nsresult
 nsHttpChannel::MaybeRaceCacheWithNetwork()
 {
     // Don't trigger the network if the load flags say so.
     if (mLoadFlags & (LOAD_ONLY_FROM_CACHE | LOAD_NO_NETWORK_IO)) {
         return NS_OK;
     }
 
+    // We must not race if the channel has a failure status code.
+    if (NS_FAILED(mStatus)) {
+        return NS_OK;
+    }
+
+    // If a CORS Preflight is required we must not race.
+    if (mRequireCORSPreflight && !mIsCorsPreflightDone) {
+        return NS_OK;
+    }
+
     uint32_t threshold = mCacheOpenWithPriority ? sRCWNQueueSizePriority
                                                 : sRCWNQueueSizeNormal;
     // No need to trigger to trigger the racing, since most likely the cache
     // will be faster.
     if (mCacheQueueSizeWhenOpen < threshold) {
         return NS_OK;
     }