diff --git a/rpc/shared/src/main/scala/kreuzberg/rpc/MessageCodec.scala b/rpc/shared/src/main/scala/kreuzberg/rpc/MessageCodec.scala
index f0ecada..f2f8f58 100644
--- a/rpc/shared/src/main/scala/kreuzberg/rpc/MessageCodec.scala
+++ b/rpc/shared/src/main/scala/kreuzberg/rpc/MessageCodec.scala
@@ -30,7 +30,7 @@ trait MessageCodec[T] {
 object MessageCodec {
   implicit val jsonArrayCodec: MessageCodec[String] = new MessageCodec[String] {
     import upickle.default._
-    override def combine(args: Seq[(String, String)]): String = {
+    override def combine(args: (String, String)*): String = {
       args.map(_._2).mkString("[", ",", "]")
     }