diff --git a/src/runtime/mgcmark.go b/src/runtime/mgcmark.go
index 5a24cdac88a..52267e6fb08 100644
--- a/src/runtime/mgcmark.go
+++ b/src/runtime/mgcmark.go
@@ -101,8 +101,7 @@ func gcMarkRootPrepare() {
 	// Gs may be created after this point, but it's okay that we
 	// ignore them because they begin life without any roots, so
 	// there's nothing to scan, and any roots they create during
-	// the concurrent phase will be scanned during mark
-	// termination.
+	// the concurrent phase will be caught by the write barrier.
 	work.nStackRoots = int(atomic.Loaduintptr(&allglen))
 
 	work.markrootNext = 0