diff --git a/src/remote/activitypub/act/undo/follow.ts b/src/remote/activitypub/act/undo/follow.ts
new file mode 100644
index 0000000000..b1c462a3b0
--- /dev/null
+++ b/src/remote/activitypub/act/undo/follow.ts
@@ -0,0 +1,25 @@
+import parseAcct from '../../../../acct/parse';
+import User from '../../../../models/user';
+import config from '../../../../config';
+import unfollow from '../../../../services/following/delete';
+
+export default async (actor, activity): Promise<void> => {
+	const prefix = config.url + '/@';
+	const id = activity.object.id || activity.object;
+
+	if (!id.startsWith(prefix)) {
+		return null;
+	}
+
+	const { username, host } = parseAcct(id.slice(prefix.length));
+	if (host !== null) {
+		throw new Error();
+	}
+
+	const followee = await User.findOne({ username, host });
+	if (followee === null) {
+		throw new Error();
+	}
+
+	await unfollow(actor, followee, activity);
+};
diff --git a/src/remote/activitypub/act/undo.ts b/src/remote/activitypub/act/undo/index.ts
similarity index 89%
rename from src/remote/activitypub/act/undo.ts
rename to src/remote/activitypub/act/undo/index.ts
index 9d9f6b0359..ecd9944b42 100644
--- a/src/remote/activitypub/act/undo.ts
+++ b/src/remote/activitypub/act/undo/index.ts
@@ -1,4 +1,4 @@
-import unfollow from './unfollow';
+import unfollow from './follow';
 
 export default async (actor, activity): Promise<void> => {
 	if ('actor' in activity && actor.account.uri !== activity.actor) {