diff --git a/app/lib/activitypub/tag_manager.rb b/app/lib/activitypub/tag_manager.rb
index e3bf33ec59..74915e8405 100644
--- a/app/lib/activitypub/tag_manager.rb
+++ b/app/lib/activitypub/tag_manager.rb
@@ -274,10 +274,9 @@ class ActivityPub::TagManager
 
     path_params = Rails.application.routes.recognize_path(uri)
 
-    # TODO: handle numeric IDs
     case path_params[:controller]
     when 'accounts'
-      [:username, path_params[:username]]
+      path_params.key?(:username) ? [:username, path_params[:username]] : [:id, path_params[:id]]
     when 'instance_actors'
       [:id, -99]
     end
diff --git a/spec/services/activitypub/synchronize_followers_service_spec.rb b/spec/services/activitypub/synchronize_followers_service_spec.rb
index 70f27627e1..4544dabb02 100644
--- a/spec/services/activitypub/synchronize_followers_service_spec.rb
+++ b/spec/services/activitypub/synchronize_followers_service_spec.rb
@@ -6,7 +6,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
   subject { described_class.new }
 
   let(:actor)          { Fabricate(:account, domain: 'example.com', uri: 'http://example.com/account', inbox_url: 'http://example.com/inbox') }
-  let(:alice)          { Fabricate(:account, username: 'alice') }
+  let(:alice)          { Fabricate(:account, username: 'alice', id_scheme: :numeric_ap_id) }
   let(:bob)            { Fabricate(:account, username: 'bob') }
   let(:eve)            { Fabricate(:account, username: 'eve') }
   let(:mallory)        { Fabricate(:account, username: 'mallory') }