diff --git a/smtp.go b/smtp.go
index 14ab8c1..50ad638 100644
--- a/smtp.go
+++ b/smtp.go
@@ -137,12 +137,8 @@ func (c *Client) ehlo() error {
 	if len(extList) > 1 {
 		extList = extList[1:]
 		for _, line := range extList {
-			args := strings.SplitN(line, " ", 2)
-			if len(args) > 1 {
-				ext[args[0]] = args[1]
-			} else {
-				ext[args[0]] = ""
-			}
+			k, v, _ := strings.Cut(line, " ")
+			ext[k] = v
 		}
 	}
 	if mechs, ok := ext["AUTH"]; ok {