diff --git a/lib/client.js b/lib/client.js
index 4ee4465..ae354b6 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -112,7 +112,7 @@ class Client {
         return;
       }
       const result = await proc.method(args);
-      if (!session && proc.access === 'public') {
+      if (!session && result && result.userId && proc.access === 'public') {
         session = application.auth.start(this, result.userId);
         result.token = session.token;
       }