diff --git a/handshake_server.go b/handshake_server.go
index bbce606..2ea6da6 100644
--- a/handshake_server.go
+++ b/handshake_server.go
@@ -229,7 +229,7 @@ func (hs *serverHandshakeState) processClientHello() error {
 	}
 
 	if !foundCompression {
-		c.sendAlert(alertHandshakeFailure)
+		c.sendAlert(alertIllegalParameter)
 		return errors.New("tls: client does not support uncompressed connections")
 	}