diff --git a/src/activitypub/helpers.js b/src/activitypub/helpers.js
index fefeb8be06..be430eb2f5 100644
--- a/src/activitypub/helpers.js
+++ b/src/activitypub/helpers.js
@@ -94,10 +94,9 @@ Helpers.resolveLocalUid = async (input) => {
 		const { host, pathname } = new URL(input);
 
 		if (host === nconf.get('url_parsed').host) {
-			slug = pathname.replace(nconf.get('relative_path'), '').split('/').filter(Boolean)[1];
-		} else {
-			throw new Error('[[error:activitypub.invalid-id]]');
+			return pathname.replace(nconf.get('relative_path'), '').split('/').filter(Boolean)[1];
 		}
+		throw new Error('[[error:activitypub.invalid-id]]');
 	} else if (input.indexOf('@') !== -1) { // Webfinger
 		([slug] = input.replace(/^acct:/, '').split('@'));
 	} else {
diff --git a/src/activitypub/inbox.js b/src/activitypub/inbox.js
index 4a5efec706..26be56e76a 100644
--- a/src/activitypub/inbox.js
+++ b/src/activitypub/inbox.js
@@ -124,8 +124,8 @@ inbox.undo = async (req) => {
 
 	if (type === 'Follow') {
 		await Promise.all([
-			db.sortedSetRemove(`followingRemote:${uid}`, actor),
-			db.decrObjectField(`user:${uid}`, 'followingRemoteCount'),
+			db.sortedSetRemove(`followersRemote:${uid}`, actor),
+			db.decrObjectField(`user:${uid}`, 'followerRemoteCount'),
 		]);
 	}
 };
diff --git a/src/activitypub/index.js b/src/activitypub/index.js
index 6f276a4f06..d783f12e9a 100644
--- a/src/activitypub/index.js
+++ b/src/activitypub/index.js
@@ -190,12 +190,11 @@ ActivityPub.send = async (uid, targets, payload) => {
 		targets = [targets];
 	}
 
-	const userslug = await user.getUserField(uid, 'userslug');
 	const inboxes = await ActivityPub.resolveInboxes(targets);
 
 	payload = {
 		'@context': 'https://www.w3.org/ns/activitystreams',
-		actor: `${nconf.get('url')}/user/${userslug}`,
+		actor: `${nconf.get('url')}/uid/${uid}`,
 		...payload,
 	};
 
diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index 374d4dc994..982a840fee 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -24,7 +24,6 @@ Mocks.profile = async (actors) => {
 			postcount, inbox, endpoints,
 		} = actor;
 		const { hostname } = new URL(actor.id);
-		// const isFollowing = await db.isSortedSetMember(`followingRemote:${callerUid}`, uid);
 
 		let picture;
 		if (icon) {
diff --git a/src/api/activitypub.js b/src/api/activitypub.js
index 23b0d0363a..429c6e8afc 100644
--- a/src/api/activitypub.js
+++ b/src/api/activitypub.js
@@ -12,7 +12,6 @@ const nconf = require('nconf');
 
 const db = require('../database');
 const activitypub = require('../activitypub');
-const user = require('../user');
 const posts = require('../posts');
 
 const activitypubApi = module.exports;
@@ -23,24 +22,23 @@ activitypubApi.follow = async (caller, { uid } = {}) => {
 		throw new Error('[[error:activitypub.invalid-id]]');
 	}
 
-	await activitypub.send(caller.uid, uid, {
+	await activitypub.send(caller.uid, [result.actorUri], {
 		type: 'Follow',
 		object: result.actorUri,
 	});
 };
 
 activitypubApi.unfollow = async (caller, { uid }) => {
-	const userslug = await user.getUserField(caller.uid, 'userslug');
 	const result = await activitypub.helpers.query(uid);
 	if (!result) {
 		throw new Error('[[error:activitypub.invalid-id]]');
 	}
 
-	await activitypub.send(caller.uid, uid, {
+	await activitypub.send(caller.uid, [result.actorUri], {
 		type: 'Undo',
 		object: {
 			type: 'Follow',
-			actor: `${nconf.get('url')}/user/${userslug}`,
+			actor: `${nconf.get('url')}/uid/${caller.uid}`,
 			object: result.actorUri,
 		},
 	});
diff --git a/src/user/follow.js b/src/user/follow.js
index a15ecb121f..ec7e36f10f 100644
--- a/src/user/follow.js
+++ b/src/user/follow.js
@@ -2,6 +2,7 @@
 'use strict';
 
 const plugins = require('../plugins');
+const activitypub = require('../activitypub');
 const db = require('../database');
 
 module.exports = function (User) {
@@ -88,9 +89,11 @@ module.exports = function (User) {
 	}
 
 	User.isFollowing = async function (uid, theirid) {
-		if (parseInt(uid, 10) <= 0 || parseInt(theirid, 10) <= 0) {
+		const isRemote = activitypub.helpers.isUri(theirid);
+		if (parseInt(uid, 10) <= 0 || (!isRemote && (theirid, 10) <= 0)) {
 			return false;
 		}
-		return await db.isSortedSetMember(`following:${uid}`, theirid);
+		const setPrefix = isRemote ? 'followingRemote' : 'following';
+		return await db.isSortedSetMember(`${setPrefix}:${uid}`, theirid);
 	};
 };
diff --git a/test/activitypub.js b/test/activitypub.js
index ca28f3423e..4221bee43c 100644
--- a/test/activitypub.js
+++ b/test/activitypub.js
@@ -442,6 +442,8 @@ describe('ActivityPub integration', () => {
 				it('should properly save the mainPid in the topic hash', async () => {
 					assert.strictEqual(topic.mainPid, note.id);
 				});
+
+				// todo: test topic replies, too
 			});
 		});
 	});