diff --git a/cmd/dataxl/main.go b/cmd/dataxl/main.go
index 957ccbc..af25a8c 100644
--- a/cmd/dataxl/main.go
+++ b/cmd/dataxl/main.go
@@ -52,7 +52,7 @@ func run(args []string, stdin io.Reader, stdout, stderr io.Writer) error {
 	fs.StringVar(&opt.sheet, "sheet", "Sheet1", "worksheet name for xlsx input/output")
 	fs.BoolVar(&opt.pretty, "pretty", true, "pretty-print structured output")
 	fs.Usage = func() {
-		fmt.Fprintln(stderr, `Usage:
+		_, _ = fmt.Fprintln(stderr, `Usage:
   dataxl -from yaml -to tsv -i input.yaml -o output.tsv
   dataxl -from tsv -to json < paste-from-excel.tsv
   dataxl -from json -to xlsx -i data.json -o data.xlsx
@@ -150,7 +150,7 @@ func writeOutput(path string, stdout io.Writer, data []byte) error {
 		_, err := stdout.Write(data)
 		return err
 	}
-	return os.WriteFile(path, data, 0644)
+	return os.WriteFile(path, data, 0o644)
 }
 
 func normalizeFormat(format string) string {