diff --git a/openrpc-client.asd b/openrpc-client.asd
index 2e78cbc..b38e3e1 100644
--- a/openrpc-client.asd
+++ b/openrpc-client.asd
@@ -5,6 +5,7 @@
   :class :40ants-asdf-system
   :defsystem-depends-on ("40ants-asdf-system")
   :pathname "client"
+  :serial t
   :depends-on ("jsonrpc"
                "openrpc-client/client")
   :description "OpenRPC client implementation for Common Lisp."