diff --git a/protocol/errorsHelp.json b/protocol/errorsHelp.json
index 59ec5ab..eb6fe3a 100644
--- a/protocol/errorsHelp.json
+++ b/protocol/errorsHelp.json
@@ -14,6 +14,7 @@
   "40012": "https://faqs.ably.com/error-code-40012-invalid-client-id",
   "40013": "https://faqs.ably.com/error-code-40013",
   "40016": "https://faqs.ably.com/error-code-40016",
+  "40020": "https://faqs.ably.com/error-code-40020",
   "40022": "https://faqs.ably.com/error-code-40022",
   "40030": "https://faqs.ably.com/error-code-40030",
   "40031": "https://faqs.ably.com/client-specified-message-id-restrictions-for-multiple-messages-published-atomically",