diff --git a/smtp.go b/smtp.go
index 50ad638..84fe2d4 100644
--- a/smtp.go
+++ b/smtp.go
@@ -106,7 +106,7 @@ func (c *Client) Hello(localName string) error {
 }
 
 // cmd is a convenience function that sends a command and returns the response
-func (c *Client) cmd(expectCode int, format string, args ...interface{}) (int, string, error) {
+func (c *Client) cmd(expectCode int, format string, args ...any) (int, string, error) {
 	id, err := c.Text.Cmd(format, args...)
 	if err != nil {
 		return 0, "", err