diff --git a/app/services/activitypub/process_account_service.rb b/app/services/activitypub/process_account_service.rb
index 563fa5aa07..4149fd9c4e 100644
--- a/app/services/activitypub/process_account_service.rb
+++ b/app/services/activitypub/process_account_service.rb
@@ -209,7 +209,7 @@ class ActivityPub::ProcessAccountService < BaseService
   end
 
   def fetch_instance_info
-    FetchInstanceInfoWorker.perform_async(@account.domain) unless InstanceInfo.exists?(domain: @account.domain)
+    ActivityPub::FetchInstanceInfoWorker.perform_async(@account.domain) unless InstanceInfo.exists?(domain: @account.domain)
   end
 
   def actor_type
diff --git a/app/workers/fetch_instance_info_worker.rb b/app/workers/activitypub/fetch_instance_info_worker.rb
similarity index 88%
rename from app/workers/fetch_instance_info_worker.rb
rename to app/workers/activitypub/fetch_instance_info_worker.rb
index 2700f88e13..e982d4c086 100644
--- a/app/workers/fetch_instance_info_worker.rb
+++ b/app/workers/activitypub/fetch_instance_info_worker.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class FetchInstanceInfoWorker
+class ActivityPub::FetchInstanceInfoWorker
   include Sidekiq::Worker
   include JsonLdHelper
   include Redisable
@@ -64,9 +64,9 @@ class FetchInstanceInfoWorker
 
         body_to_json(response.body_with_limit)
       elsif response.code == 410
-        raise FetchInstanceInfoWorker::GoneError, "#{domain} is gone from the server"
+        raise ActivityPub::FetchInstanceInfoWorker::GoneError, "#{@instance.domain} is gone from the server"
       else
-        raise FetchInstanceInfoWorker::RequestError, "Request for #{domain} returned HTTP #{response.code}"
+        raise ActivityPub::FetchInstanceInfoWorker::RequestError, "Request for #{@instance.domain} returned HTTP #{response.code}"
       end
     end
   end
diff --git a/app/workers/scheduler/update_instance_info_scheduler.rb b/app/workers/scheduler/update_instance_info_scheduler.rb
index 0587146b32..f5b2852859 100644
--- a/app/workers/scheduler/update_instance_info_scheduler.rb
+++ b/app/workers/scheduler/update_instance_info_scheduler.rb
@@ -7,7 +7,7 @@ class Scheduler::UpdateInstanceInfoScheduler
 
   def perform
     Instance.select(:domain).reorder(nil).find_in_batches do |instances|
-      FetchInstanceInfoWorker.push_bulk(instances) do |instance|
+      ActivityPub::FetchInstanceInfoWorker.push_bulk(instances) do |instance|
         [instance.domain]
       end
     end
diff --git a/spec/workers/activitypub/fetch_instance_info_worker_spec.rb b/spec/workers/activitypub/fetch_instance_info_worker_spec.rb
new file mode 100644
index 0000000000..3561df72af
--- /dev/null
+++ b/spec/workers/activitypub/fetch_instance_info_worker_spec.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe ActivityPub::FetchInstanceInfoWorker do
+  subject { described_class.new }
+
+  let(:wellknown_nodeinfo) do
+    {
+      links: [
+        {
+          rel: 'http://nodeinfo.diaspora.software/ns/schema/2.0',
+          href: 'https://example.com/nodeinfo/2.0',
+        },
+      ],
+    }
+  end
+
+  let(:nodeinfo) do
+    {
+      version: '2.0',
+      software: {
+        name: 'mastodon',
+        version: '4.2.0-beta1',
+      },
+      protocols: ['activitypub'],
+    }
+  end
+
+  let(:wellknown_nodeinfo_json) { Oj.dump(wellknown_nodeinfo) }
+  let(:nodeinfo_json) { Oj.dump(nodeinfo) }
+
+  context 'when success' do
+    before do
+      stub_request(:get, 'https://example.com/.well-known/nodeinfo').to_return(status: 200, body: wellknown_nodeinfo_json)
+      stub_request(:get, 'https://example.com/nodeinfo/2.0').to_return(status: 200, body: nodeinfo_json)
+      Fabricate(:account, domain: 'example.com')
+      Instance.refresh
+    end
+
+    it 'performs a mastodon instance' do
+      subject.perform('example.com')
+
+      info = InstanceInfo.find_by(domain: 'example.com')
+      expect(info).to_not be_nil
+      expect(info.software).to eq 'mastodon'
+      expect(info.version).to eq '4.2.0-beta1'
+    end
+  end
+
+  context 'when failed' do
+    before do
+      stub_request(:get, 'https://example.com/.well-known/nodeinfo').to_return(status: 404)
+      Fabricate(:account, domain: 'example.com')
+      Instance.refresh
+    end
+
+    it 'performs a mastodon instance' do
+      expect { subject.perform('example.com') }.to raise_error(ActivityPub::FetchInstanceInfoWorker::RequestError, 'Request for example.com returned HTTP 404')
+
+      info = InstanceInfo.find_by(domain: 'example.com')
+      expect(info).to be_nil
+    end
+  end
+end