diff --git a/ably.d.ts b/ably.d.ts
index 05293a76a..256123209 100644
--- a/ably.d.ts
+++ b/ably.d.ts
@@ -683,7 +683,8 @@ export type capabilityOp =
   | 'stats'
   | 'channel-metadata'
   | 'push-subscribe'
-  | 'push-admin';
+  | 'push-admin'
+  | 'privileged-headers';
 
 /**
  * Capabilities which are available for use within {@link TokenParams}.