diff --git a/src/cmd/compile/internal/gc/racewalk.go b/src/cmd/compile/internal/gc/racewalk.go
index 4a658b19766..ad2bba97142 100644
--- a/src/cmd/compile/internal/gc/racewalk.go
+++ b/src/cmd/compile/internal/gc/racewalk.go
@@ -164,7 +164,7 @@ func instrumentnode(np **Node, init *Nodes, wr int, skip int) {
 				var outn Nodes
 				outn.Set(out)
 				instrumentnode(&ls[i], &outn, 0, 0)
-				if ls[i].Op != OAS || ls[i].Ninit.Len() == 0 {
+				if ls[i].Op != OAS && ls[i].Op != OASWB && ls[i].Op != OAS2FUNC || ls[i].Ninit.Len() == 0 {
 					out = append(outn.Slice(), ls[i])
 				} else {
 					// Splice outn onto end of ls[i].Ninit
diff --git a/test/fixedbugs/issue16008.go b/test/fixedbugs/issue16008.go
new file mode 100644
index 00000000000..1b516fbabef
--- /dev/null
+++ b/test/fixedbugs/issue16008.go
@@ -0,0 +1,52 @@
+// errorcheck -0 -race
+
+package foo
+
+const benchmarkNumNodes = 10000
+
+func BenchmarkUpdateNodeTransaction(b B) {
+	s, nodeIDs := setupNodes(benchmarkNumNodes)
+	b.ResetTimer()
+	for i := 0; i < b.N(); i++ {
+		_ = s.Update(func(tx1 Tx) error {
+			_ = UpdateNode(tx1, &Node{
+				ID: nodeIDs[i%benchmarkNumNodes],
+			})
+			return nil
+		})
+	}
+}
+
+type B interface {
+	ResetTimer()
+	N() int
+}
+
+type Tx interface {
+}
+
+type Node struct {
+	ID string
+}
+
+type MemoryStore struct {
+}
+
+// go:noinline
+func setupNodes(n int) (s *MemoryStore, nodeIDs []string) {
+	return
+}
+
+//go:noinline
+func (s *MemoryStore) Update(cb func(Tx) error) error {
+	return nil
+}
+
+var sink interface{}
+
+//go:noinline
+func UpdateNode(tx Tx, n *Node) error {
+	sink = tx
+	sink = n
+	return nil
+}