diff --git a/decor/speed.go b/decor/speed.go
index f3355c4..da8b253 100644
--- a/decor/speed.go
+++ b/decor/speed.go
@@ -82,7 +82,7 @@
 	zDur     time.Duration
 }
 
-func (d *movingAverageSpeed) Decor(s Statistics) (string, int) {
+func (d *movingAverageSpeed) Decor(_ Statistics) (string, int) {
 	var str string
 	// ewma implementation may return 0 before accumulating certain number of samples
 	if v := d.average.Value(); v != 0 {