diff --git a/src/activitypub/actors.js b/src/activitypub/actors.js
index 6516523849..1962294a24 100644
--- a/src/activitypub/actors.js
+++ b/src/activitypub/actors.js
@@ -401,12 +401,10 @@ Actors.assertGroup = async (ids, options = {}) => {
 	]);
 
 	// Privilege mask
-	const masksAdd = categoryObjs.reduce((sets, category) => {
-		if (category?._activitypub?.postingRestrictedToMods) {
-			sets.push(`cid:${category.cid}:privilegeMask`);
-		}
-		return sets;
-	}, []);
+	const [masksAdd, masksRemove] = categoryObjs.reduce(([add, remove], category) => {
+		(category?._activitypub?.postingRestrictedToMods ? add : remove).push(`cid:${category.cid}:privilegeMask`);
+		return [add, remove];
+	}, [[], []]);
 
 	await Promise.all([
 		db.setObjectBulk(bulkSet),
@@ -415,6 +413,7 @@ Actors.assertGroup = async (ids, options = {}) => {
 		db.setObject('handle:cid', queries.handleAdd),
 		_migratePersonToGroup(categoryObjs),
 		db.setsAdd(masksAdd, 'topics:create'),
+		db.setsRemove(masksRemove, 'topics:create'),
 	]);
 
 	return categoryObjs;
diff --git a/test/activitypub/privileges.js b/test/activitypub/privileges.js
index 89fdb83245..695c2a2226 100644
--- a/test/activitypub/privileges.js
+++ b/test/activitypub/privileges.js
@@ -250,7 +250,7 @@ describe('Privilege masking', () => {
 		});
 	});
 
-	describe('postingRestrictedToMods', () => {
+	describe('postingRestrictedToMods (true on assert)', () => {
 		let cid;
 		let uid;
 
@@ -297,4 +297,147 @@ describe('Privilege masking', () => {
 			assert(!set['topics:create']);
 		});
 	});
+
+	describe('postingRestrictedToMods (true on assert and re-assertion)', () => {
+		let cid;
+		let uid;
+
+		before(async () => {
+			// Set up a mock group with `postingRestrictedToMods` bit set
+			({ id: cid } = helpers.mocks.group({
+				postingRestrictedToMods: true,
+			}));
+
+			// Unprivileged user for testing
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+
+			// Assert group, then re-assert again
+			await activitypub.actors.assertGroup([cid]);
+			await activitypub.actors.assertGroup([cid], { update: true });
+		});
+
+		it('should fail the privileges .can() check if requested', async () => {
+			const can = await privileges.categories.can('topics:create', cid, uid);
+			assert(!can);
+		});
+
+		it('should return false in the privilege set when requested', async () => {
+			const set = await privileges.categories.get(cid, uid);
+
+			assert(set);
+			assert(!set['topics:create']);
+		});
+	});
+
+	describe('postingRestrictedToMods (true on assert, false on update)', () => {
+		let cid;
+		let uid;
+
+		before(async () => {
+			// Set up a mock group with `postingRestrictedToMods` bit set
+			({ id: cid } = helpers.mocks.group({
+				postingRestrictedToMods: true,
+			}));
+
+			// Unprivileged user for testing
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+
+			await activitypub.actors.assertGroup([cid]);
+
+			// Group updated "remotely"
+			helpers.mocks.group({
+				id: cid,
+				postingRestrictedToMods: false,
+			});
+		});
+
+		it('should remove the privilege mask if the bit is not present on group actor update', async () => {
+			let can = await privileges.categories.can('topics:create', cid, uid);
+			assert(!can, 'Initial state should be denied due to mask.');
+
+			// Group re-assertion
+			await activitypub.actors.assertGroup([cid], { update: true });
+
+			// Ensure mask is gone from db
+			const exists = await db.exists(`cid:${cid}:privilegeMask`);
+			assert(!exists);
+
+			can = await privileges.categories.can('topics:create', cid, uid);
+			assert(can, 'Privilege should be restored after mask removal.');
+		});
+	});
+
+	describe('postingRestrictedToMods (true on assert, property missing on update)', () => {
+		let cid;
+		let uid;
+
+		before(async () => {
+			// Set up a mock group with `postingRestrictedToMods` bit set
+			({ id: cid } = helpers.mocks.group({
+				postingRestrictedToMods: true,
+			}));
+
+			// Unprivileged user for testing
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+
+			await activitypub.actors.assertGroup([cid]);
+
+			// Group updated "remotely"
+			helpers.mocks.group({
+				id: cid,
+			});
+		});
+
+		it('should remove the privilege mask if the bit is not present on group actor update', async () => {
+			let can = await privileges.categories.can('topics:create', cid, uid);
+			assert(!can, 'Initial state should be denied due to mask.');
+
+			// Group re-assertion
+			await activitypub.actors.assertGroup([cid], { update: true });
+
+			// Ensure mask is gone from db
+			const exists = await db.exists(`cid:${cid}:privilegeMask`);
+			assert(!exists);
+
+			can = await privileges.categories.can('topics:create', cid, uid);
+			assert(can, 'Privilege should be restored after mask removal.');
+		});
+	});
+
+	describe('postingRestrictedToMods (false on assert, true on update)', () => {
+		let cid;
+		let uid;
+
+		before(async () => {
+			// Set up a mock group with `postingRestrictedToMods` bit set to false
+			({ id: cid } = helpers.mocks.group({
+				postingRestrictedToMods: false,
+			}));
+
+			// Unprivileged user for testing
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+
+			await activitypub.actors.assertGroup([cid]);
+
+
+			// Update group "remotely", re-assert
+			helpers.mocks.group({
+				id: cid,
+				postingRestrictedToMods: true,
+			});
+			await activitypub.actors.assertGroup([cid], { update: true });
+		});
+
+		it('should fail the privileges .can() check if requested', async () => {
+			const can = await privileges.categories.can('topics:create', cid, uid);
+			assert(!can);
+		});
+
+		it('should return false in the privilege set when requested', async () => {
+			const set = await privileges.categories.get(cid, uid);
+
+			assert(set);
+			assert(!set['topics:create']);
+		});
+	});
 });
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