diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 8be915620b48c..e99ec1422d97e 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -1887,6 +1887,15 @@ void SpdySession::ResetStreamIterator(ActiveStreamMap::iterator it,
   RequestPriority priority = it->second->priority();
   EnqueueResetStreamFrame(stream_id, priority, error_code, description);
 
+  // EnqueueResetStreamFrame() can synchronously call DoDrainSession() ->
+  // StartGoingAway() -> CloseActiveStreamIterator(), which erases entries
+  // from |active_streams_| and invalidates |it|. Re-look-up the stream by
+  // ID; if it was already closed by the drain, there is nothing left to do.
+  it = active_streams_.find(stream_id);
+  if (it == active_streams_.end()) {
+    return;
+  }
+
   // Removes any pending writes for the stream except for possibly an
   // in-flight one.
   CloseActiveStreamIterator(it, error);