diff --git a/src/cmd/compile/internal/gc/bexport.go b/src/cmd/compile/internal/gc/bexport.go
index b49f0fb..3edd048 100644
--- a/src/cmd/compile/internal/gc/bexport.go
+++ b/src/cmd/compile/internal/gc/bexport.go
@@ -877,7 +877,7 @@
 // tracef is like fmt.Printf but it rewrites the format string
 // to take care of indentation.
 func (p *exporter) tracef(format string, args ...interface{}) {
-	if strings.IndexAny(format, "<>\n") >= 0 {
+	if strings.ContainsAny(format, "<>\n") {
 		var buf bytes.Buffer
 		for i := 0; i < len(format); i++ {
 			// no need to deal with runes