diff --git a/lib/types/thread-permission-types.js b/lib/types/thread-permission-types.js
--- a/lib/types/thread-permission-types.js
+++ b/lib/types/thread-permission-types.js
@@ -169,16 +169,12 @@
   threadPermissionPropagationPrefixes.DESCENDANT +
   threadPermissionFilterPrefixes.TOP_LEVEL +
   threadPermissions.JOIN_THREAD;
-const descendantJoinThread =
-  threadPermissionPropagationPrefixes.DESCENDANT +
-  threadPermissions.JOIN_THREAD;
 const childJoinThread =
   threadPermissionPropagationPrefixes.CHILD + threadPermissions.JOIN_THREAD;
 const knowOfSecretChannelsPermissions = new Set([
   descendantKnowOf,
   descendantVisible,
   descendantTopLevelJoinThread,
-  descendantJoinThread,
   childJoinThread,
 ]);