diff --git a/src/runtime/time.go b/src/runtime/time.go
index d338705b7c..8ab2a03430 100644
--- a/src/runtime/time.go
+++ b/src/runtime/time.go
@@ -609,8 +609,14 @@ func moveTimers(pp *p, timers []*timer) {
 		for {
 			switch s := atomic.Load(&t.status); s {
 			case timerWaiting:
+				if !atomic.Cas(&t.status, s, timerMoving) {
+					continue
+				}
 				t.pp = 0
 				doaddtimer(pp, t)
+				if !atomic.Cas(&t.status, timerMoving, timerWaiting) {
+					badTimer()
+				}
 				break loop
 			case timerModifiedEarlier, timerModifiedLater:
 				if !atomic.Cas(&t.status, s, timerMoving) {