diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
index fd91509f42f0..8cafa8804a7a 100644
--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -3128,6 +3128,9 @@ nsHttpChannel::OnDoneReadingPartialCacheEntry(bool *streamDone)
     // we're now completing the cached content, so we can clear this flag.
     // this puts us in the state of a regular download.
     mCachedContentIsPartial = false;
+    // The cache input stream pump is finished, we do not need it any more.
+    // (see bug 1313923)
+    mCachePump = nullptr;
 
     // resume the transaction if it exists, otherwise the pipe contained the
     // remaining part of the document and we've now streamed all of the data.