diff --git a/src/activitypub/inbox.js b/src/activitypub/inbox.js
index c2d1d60247..2f526c6477 100644
--- a/src/activitypub/inbox.js
+++ b/src/activitypub/inbox.js
@@ -109,13 +109,10 @@ inbox.follow = async (req) => {
 		}
 
 		const watchState = await categories.getWatchState([id], req.body.actor);
-		if (watchState === categories.watchStates.tracking) {
-			// No additional parsing required
-			return;
+		if (watchState[0] !== categories.watchStates.tracking) {
+			await user.setCategoryWatchState(req.body.actor, id, categories.watchStates.tracking);
 		}
 
-		await user.setCategoryWatchState(req.body.actor, id, categories.watchStates.tracking);
-
 		await activitypub.send('cid', id, req.body.actor, {
 			type: 'Accept',
 			object: {
@@ -149,10 +146,9 @@ inbox.accept = async (req) => {
 
 	if (type === 'Follow') {
 		const now = Date.now();
-		await Promise.all([
-			db.sortedSetAdd(`followingRemote:${uid}`, now, actor),
-			db.incrObjectField(`user:${uid}`, 'followingRemoteCount'),
-		]);
+		await db.sortedSetAdd(`followingRemote:${uid}`, now, actor);
+		const followingRemoteCount = await db.sortedSetCard(`followingRemote:${uid}`);
+		await user.setUserField(uid, 'followingRemoteCount', followingRemoteCount);
 	}
 };
 
@@ -177,10 +173,9 @@ inbox.undo = async (req) => {
 						throw new Error('[[error:invalid-uid]]');
 					}
 
-					await Promise.all([
-						db.sortedSetRemove(`followersRemote:${id}`, actor),
-						db.decrObjectField(`user:${id}`, 'followerRemoteCount'),
-					]);
+					await db.sortedSetRemove(`followersRemote:${id}`, actor);
+					const followerRemoteCount = await db.sortedSetCard(`followerRemote:${id}`);
+					await user.setUserField(id, 'followerRemoteCount', followerRemoteCount);
 					break;
 				}
 
diff --git a/src/activitypub/index.js b/src/activitypub/index.js
index 63ec8eca49..b3b68c5057 100644
--- a/src/activitypub/index.js
+++ b/src/activitypub/index.js
@@ -41,7 +41,7 @@ ActivityPub.getPublicKey = async (type, id) => {
 	let publicKey;
 
 	try {
-		({ publicKey } = await db.getObject(`uid:${id}:keys`));
+		({ publicKey } = await db.getObject(`${type}:${id}:keys`));
 	} catch (e) {
 		({ publicKey } = await ActivityPub.helpers.generateKeys(type, id));
 	}
@@ -145,6 +145,7 @@ ActivityPub.verify = async (req) => {
 		return memo;
 	}, []).join('\n');
 
+
 	// Verify the signature string via public key
 	try {
 		// Retrieve public key from remote instance
@@ -196,9 +197,25 @@ ActivityPub.send = async (type, id, targets, payload) => {
 
 	const inboxes = await ActivityPub.resolveInboxes(targets);
 
+	let actor;
+	switch (type) {
+		case 'uid': {
+			actor = `${nconf.get('url')}/uid/${id}`;
+			break;
+		}
+
+		case 'cid': {
+			actor = `${nconf.get('url')}/category/${id}`;
+			break;
+		}
+
+		default:
+			throw new Error('[[error:activitypub.invalid-id]]');
+	}
+
 	payload = {
 		'@context': 'https://www.w3.org/ns/activitystreams',
-		actor: `${nconf.get('url')}/uid/${id}`,
+		actor,
 		...payload,
 	};
 
@@ -220,3 +237,10 @@ ActivityPub.send = async (type, id, targets, payload) => {
 		}
 	}));
 };
+
+setTimeout(async () => {
+	await ActivityPub.send('uid', 1, 'https://localhost/category/1', {
+		type: 'Follow',
+		object: 'https://localhost/category/1',
+	});
+}, 2000);
diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index 1e4e017f10..4074bc57f7 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -164,6 +164,7 @@ Mocks.actors.user = async (uid) => {
 
 Mocks.actors.category = async (cid) => {
 	let { name, slug, description: summary, backgroundImage } = await categories.getCategoryData(cid);
+	const publicKey = await activitypub.getPublicKey('cid', cid);
 
 	if (backgroundImage) {
 		const filename = utils.decodeHTMLEntities(backgroundImage).split('/').pop();
@@ -189,6 +190,12 @@ Mocks.actors.category = async (cid) => {
 		preferredUsername: `cid.${cid}`,
 		summary,
 		icon: backgroundImage,
+
+		publicKey: {
+			id: `${nconf.get('url')}/category/${cid}#key`,
+			owner: `${nconf.get('url')}/category/${cid}`,
+			publicKeyPem: publicKey,
+		},
 	};
 };