diff --git a/src/cmd/compile/internal/gc/range.go b/src/cmd/compile/internal/gc/range.go
index bf30d9388e..cbe69a1ebc 100644
--- a/src/cmd/compile/internal/gc/range.go
+++ b/src/cmd/compile/internal/gc/range.go
@@ -588,6 +588,7 @@ func arrayClear(n, v1, v2, a *Node) bool {
 	var fn *Node
 	if types.Haspointers(a.Type.Elem()) {
 		// memclrHasPointers(hp, hn)
+		Curfn.Func.setWBPos(stmt.Pos)
 		fn = mkcall("memclrHasPointers", nil, nil, hp, hn)
 	} else {
 		// memclrNoHeapPointers(hp, hn)
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index 528aacb213..b84bc26e04 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -2860,6 +2860,7 @@ func extendslice(n *Node, init *Nodes) *Node {
 	hasPointers := types.Haspointers(elemtype)
 	if hasPointers {
 		clrname = "memclrHasPointers"
+		Curfn.Func.setWBPos(n.Pos)
 	}
 
 	var clr Nodes