diff --git a/cmd/vet/unused.go b/cmd/vet/unused.go
index cbec9bb8..db988fe1 100644
--- a/cmd/vet/unused.go
+++ b/cmd/vet/unused.go
@@ -13,7 +13,6 @@ import (
 	"go/token"
 	"strings"
 
-	"golang.org/x/tools/go/ast/astutil"
 	"golang.org/x/tools/go/types"
 )
 
@@ -56,11 +55,11 @@ func initUnusedFlags() {
 }
 
 func checkUnusedResult(f *File, n ast.Node) {
-	call, ok := astutil.Unparen(n.(*ast.ExprStmt).X).(*ast.CallExpr)
+	call, ok := unparen(n.(*ast.ExprStmt).X).(*ast.CallExpr)
 	if !ok {
 		return // not a call statement
 	}
-	fun := astutil.Unparen(call.Fun)
+	fun := unparen(call.Fun)
 
 	if f.pkg.types[fun].IsType() {
 		return // a conversion, not a call