diff --git a/stream/mts/psi/helpers.go b/stream/mts/psi/helpers.go
index 86e6cc72..82d7ce72 100644
--- a/stream/mts/psi/helpers.go
+++ b/stream/mts/psi/helpers.go
@@ -106,14 +106,11 @@ func UpdateLocation(d []byte, s string) error {
 	if !HasLocation(d) {
 		return errors.New("pmt does not location descriptor, cannot update")
 	}
-	sb := []byte(s)
-	locBytes := d[LocationDataIndx : LocationDataIndx+LocationDataSize]
-	for i, _ := range locBytes {
-		if i < len(sb) {
-			locBytes[i] = sb[i]
-		} else {
-			locBytes[i] = 0x00
-		}
+	loc := d[LocationDataIndx : LocationDataIndx+LocationDataSize]
+	n := copy(loc, s)
+	loc = loc[n:]
+	for i := range loc {
+		loc[i] = 0
 	}
 	updateCrc(d)
 	return nil