diff --git a/pkg/ueps/packet.go b/pkg/ueps/packet.go
index 65cd88d..9d5bbe1 100644
--- a/pkg/ueps/packet.go
+++ b/pkg/ueps/packet.go
@@ -108,19 +108,19 @@ func (p *PacketBuilder) MarshalAndSign(sharedSecret []byte) ([]byte, error) {
 
 // writeTLV(buf, TagVersion, []byte{0x09})
 // writeTLV(buf, TagIntent, []byte{intentID})
-func writeTLV(w io.Writer, tag uint8, value []byte) error {
+func writeTLV(writer io.Writer, tag uint8, value []byte) error {
 	// Check strict length constraint (1 byte length = max 255 bytes)
 	if len(value) > 255 {
 		return errors.New("TLV value too large for 1-byte length header")
 	}
 
-	if _, err := w.Write([]byte{tag}); err != nil {
+	if _, err := writer.Write([]byte{tag}); err != nil {
 		return err
 	}
-	if _, err := w.Write([]byte{uint8(len(value))}); err != nil {
+	if _, err := writer.Write([]byte{uint8(len(value))}); err != nil {
 		return err
 	}
-	if _, err := w.Write(value); err != nil {
+	if _, err := writer.Write(value); err != nil {
 		return err
 	}
 	return nil