diff --git a/src/runtime/chan.go b/src/runtime/chan.go
index 853a300ab52..a9ef0781cef 100644
--- a/src/runtime/chan.go
+++ b/src/runtime/chan.go
@@ -791,7 +791,7 @@ func (q *waitq) dequeue() *sudog {
 		// We use a flag in the G struct to tell us when someone
 		// else has won the race to signal this goroutine but the goroutine
 		// hasn't removed itself from the queue yet.
-		if sgp.isSelect && !atomic.Cas(&sgp.g.selectDone, 0, 1) {
+		if sgp.isSelect && !sgp.g.selectDone.CompareAndSwap(0, 1) {
 			continue
 		}
 
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 2d6602071be..19ccfcea0ee 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -487,7 +487,7 @@ type g struct {
 	cgoCtxt        []uintptr      // cgo traceback context
 	labels         unsafe.Pointer // profiler labels
 	timer          *timer         // cached timer for time.Sleep
-	selectDone     uint32         // are we participating in a select and did someone win the race?
+	selectDone     atomic.Uint32  // are we participating in a select and did someone win the race?
 
 	// goroutineProfiled indicates the status of this goroutine's stack for the
 	// current in-progress goroutine profile
diff --git a/src/runtime/select.go b/src/runtime/select.go
index 2dd6333fa7a..1072465365e 100644
--- a/src/runtime/select.go
+++ b/src/runtime/select.go
@@ -329,7 +329,7 @@ func selectgo(cas0 *scase, order0 *uint16, pc0 *uintptr, nsends, nrecvs int, blo
 
 	sellock(scases, lockorder)
 
-	gp.selectDone = 0
+	gp.selectDone.Store(0)
 	sg = (*sudog)(gp.param)
 	gp.param = nil