diff --git a/src/runtime/lockrank.go b/src/runtime/lockrank.go
index 3f9b087856..0a52e8ed3d 100644
--- a/src/runtime/lockrank.go
+++ b/src/runtime/lockrank.go
@@ -222,7 +222,7 @@ var lockPartialOrder [][]lockRank = [][]lockRank{
 	lockRankNetpollInit:   {lockRankTimers},
 
 	lockRankRwmutexW: {},
-	lockRankRwmutexR: {lockRankRwmutexW},
+	lockRankRwmutexR: {lockRankSysmon, lockRankRwmutexW},
 
 	lockRankSpanSetSpine: {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
 	lockRankGscan:        {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankFin, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot, lockRankNotifyList, lockRankProf, lockRankGcBitsArenas, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankSpanSetSpine},