--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -5858,17 +5858,19 @@ NS_IMETHODIMP nsHttpChannel::OnAuthAvail
     LOG(("nsHttpChannel::OnAuthAvailable [this=%p]", this));
 
     // setting mAuthRetryPending flag and resuming the transaction
     // triggers process of throwing away the unauthenticated data already
     // coming from the network
     mAuthRetryPending = true;
     mProxyAuthPending = false;
     LOG(("Resuming the transaction, we got credentials from user"));
-    mTransactionPump->Resume();
+    if (mTransactionPump) {
+        mTransactionPump->Resume();
+    }
 
     return NS_OK;
 }
 
 NS_IMETHODIMP nsHttpChannel::OnAuthCancelled(bool userCancel)
 {
     LOG(("nsHttpChannel::OnAuthCancelled [this=%p]", this));