diff --git a/src/cmd/go/internal/bug/bug.go b/src/cmd/go/internal/bug/bug.go
index 772b6d5dc74..e667012fbbb 100644
--- a/src/cmd/go/internal/bug/bug.go
+++ b/src/cmd/go/internal/bug/bug.go
@@ -217,7 +217,7 @@ func printGlibcVersion(w io.Writer) {
 	fmt.Fprintf(w, "%s: %s\n", m[1], firstLine(out))
 
 	// print another line (the one containing version string) in case of musl libc
-	if idx := bytes.IndexByte(out, '\n'); bytes.Index(out, []byte("musl")) != -1 && idx > -1 {
+	if idx := bytes.IndexByte(out, '\n'); bytes.Contains(out, []byte("musl")) && idx > -1 {
 		fmt.Fprintf(w, "%s\n", firstLine(out[idx+1:]))
 	}
 }