diff --git a/src/api/activitypub.js b/src/api/activitypub.js
index ddb2cd2386..4701c0ca51 100644
--- a/src/api/activitypub.js
+++ b/src/api/activitypub.js
@@ -98,7 +98,7 @@ activitypubApi.unfollow = enabledCheck(async (caller, { type, id, actor }) => {
 	}
 
 	await activitypub.send(type, id, [actor], {
-		id: `${nconf.get('url')}/${type}/${id}#activity/undo:follow/${handle}/${timestamp}`,
+		id: `${nconf.get('url')}/${type}/${id}#activity/undo:follow/${encodeURIComponent(actor)}/${timestamp}`,
 		type: 'Undo',
 		object,
 	});