diff --git a/src/runtime/mbarrier.go b/src/runtime/mbarrier.go
index acc4d14e80..fbead6d378 100644
--- a/src/runtime/mbarrier.go
+++ b/src/runtime/mbarrier.go
@@ -182,6 +182,8 @@ func gcmarkwb_m(slot *uintptr, ptr uintptr) {
 func writebarrierptr_prewrite1(dst *uintptr, src uintptr) {
 	mp := acquirem()
 	if mp.inwb || mp.dying > 0 {
+		// We explicitly allow write barriers in startpanic_m,
+		// since we're going down anyway. Ignore them here.
 		releasem(mp)
 		return
 	}
diff --git a/src/runtime/panic.go b/src/runtime/panic.go
index 90a1c0bdd1..11cb05e976 100644
--- a/src/runtime/panic.go
+++ b/src/runtime/panic.go
@@ -654,6 +654,12 @@ func recovery(gp *g) {
 	gogo(&gp.sched)
 }
 
+// startpanic_m implements unrecoverable panic.
+//
+// It can have write barriers because the write barrier explicitly
+// ignores writes once dying > 0.
+//
+//go:yeswritebarrierrec
 func startpanic_m() {
 	_g_ := getg()
 	if mheap_.cachealloc.size == 0 { // very early