diff --git a/TODO.md b/TODO.md
index 7718bb19..68c70b53 100644
--- a/TODO.md
+++ b/TODO.md
@@ -5,8 +5,8 @@
 - [ ] Pedantic state
 - [ ] brew, apt-get, rpm, chocately (windows)
 - [ ] Dynamic socket buffer sizes
-- [ ] Switch to 1.4 and use maps vs hashmaps in sublist
-- [ ] Sublist better at high concurrency
+- [ ] Switch to 1.4/1.5 and use maps vs hashmaps in sublist
+- [ ] Sublist better at high concurrency, cache uses writelock currently
 - [ ] Buffer pools/sync pools?
 - [ ] IOVec pools and writev for high fanout?
 - [ ] Add ability to reload config on signal
diff --git a/server/monitor_sort_opts.go b/server/monitor_sort_opts.go
index b91d1cf2..3959789d 100644
--- a/server/monitor_sort_opts.go
+++ b/server/monitor_sort_opts.go
@@ -53,7 +53,15 @@ func (d ByPending) Swap(i, j int) {
 	d[i], d[j] = d[j], d[i]
 }
 func (d ByPending) Less(i, j int) bool {
-	return d[i].Val.bw.Buffered() < d[j].Val.bw.Buffered()
+	client := d[i].Val
+	client.mu.Lock()
+	bwi := client.bw.Buffered()
+	client.mu.Unlock()
+	client = d[j].Val
+	client.mu.Lock()
+	bwj := client.bw.Buffered()
+	client.mu.Unlock()
+	return bwi < bwj
 }
 
 type ByOutMsgs []Pair