diff --git a/src/activitypub/actors.js b/src/activitypub/actors.js
index e414ba5bd7..b9b1843a59 100644
--- a/src/activitypub/actors.js
+++ b/src/activitypub/actors.js
@@ -400,12 +400,21 @@ Actors.assertGroup = async (ids, options = {}) => {
 		db.deleteObjectFields('handle:cid', queries.handleRemove),
 	]);
 
+	// Privilege mask
+	const masksAdd = categoryObjs.reduce((queries, category) => {
+		if (category?._activitypub?.postingRestrictedToMods) {
+			queries.push(db.setAdd.call(db, `cid:${category.cid}:privilegeMask`, 'topics:create'));
+		}
+		return queries;
+	}, []);
+
 	await Promise.all([
 		db.setObjectBulk(bulkSet),
 		db.sortedSetAdd('usersRemote:lastCrawled', groups.map(() => now), groups.map(p => p.id)),
 		db.sortedSetAddBulk(queries.searchAdd),
 		db.setObject('handle:cid', queries.handleAdd),
 		_migratePersonToGroup(categoryObjs),
+		Promise.all(masksAdd),
 	]);
 
 	return categoryObjs;
diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index 167be79263..dbebb55693 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -281,6 +281,7 @@ Mocks.category = async (actors) => {
 		let {
 			url, preferredUsername, icon, /* image, */
 			name, summary, followers, inbox, endpoints, tag,
+			postingRestrictedToMods,
 		} = actor;
 		preferredUsername = slugify(preferredUsername || name);
 		/*
@@ -338,6 +339,10 @@ Mocks.category = async (actors) => {
 			inbox,
 			sharedInbox: endpoints ? endpoints.sharedInbox : null,
 			followersUrl: followers,
+
+			_activitypub: {
+				postingRestrictedToMods,
+			},
 		};
 
 		return payload;