diff --git a/spec/lib/activitypub/activity/announce_spec.rb b/spec/lib/activitypub/activity/announce_spec.rb
index b556bfd6c2..4becf2320d 100644
--- a/spec/lib/activitypub/activity/announce_spec.rb
+++ b/spec/lib/activitypub/activity/announce_spec.rb
@@ -35,7 +35,7 @@ RSpec.describe ActivityPub::Activity::Announce do
     context 'when sender is followed by a local account' do
       before do
         Fabricate(:account).follow!(sender)
-        stub_request(:get, 'https://example.com/actor/hello-world').to_return(body: Oj.dump(unknown_object_json), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/actor/hello-world').to_return(body: JSON.generate(unknown_object_json), headers: { 'Content-Type': 'application/activity+json' })
         subject.perform
       end
 
@@ -120,7 +120,7 @@ RSpec.describe ActivityPub::Activity::Announce do
       let(:object_json) { 'https://example.com/actor/hello-world' }
 
       before do
-        stub_request(:get, 'https://example.com/actor/hello-world').to_return(body: Oj.dump(unknown_object_json), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/actor/hello-world').to_return(body: JSON.generate(unknown_object_json), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       context 'when the relay is enabled' do
diff --git a/spec/lib/activitypub/activity/create_spec.rb b/spec/lib/activitypub/activity/create_spec.rb
index 19b6014af1..3e376db3dd 100644
--- a/spec/lib/activitypub/activity/create_spec.rb
+++ b/spec/lib/activitypub/activity/create_spec.rb
@@ -1029,7 +1029,7 @@ RSpec.describe ActivityPub::Activity::Create do
         end
 
         before do
-          stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': [
               'https://www.w3.org/ns/activitystreams',
               {
@@ -1085,7 +1085,7 @@ RSpec.describe ActivityPub::Activity::Create do
         end
 
         before do
-          stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': [
               'https://www.w3.org/ns/activitystreams',
               {
@@ -1217,7 +1217,7 @@ RSpec.describe ActivityPub::Activity::Create do
       before do
         stub_request(:get, object_json[:id])
           .with(headers: { Authorization: "Bearer #{token}" })
-          .to_return(body: Oj.dump(object_json), headers: { 'Content-Type': 'application/activity+json' })
+          .to_return(body: JSON.generate(object_json), headers: { 'Content-Type': 'application/activity+json' })
 
         subject.perform
       end
diff --git a/spec/lib/activitypub/activity/quote_request_spec.rb b/spec/lib/activitypub/activity/quote_request_spec.rb
index db80448a80..d68f01211d 100644
--- a/spec/lib/activitypub/activity/quote_request_spec.rb
+++ b/spec/lib/activitypub/activity/quote_request_spec.rb
@@ -86,7 +86,7 @@ RSpec.describe ActivityPub::Activity::QuoteRequest do
 
     context 'when trying to quote a quotable local status' do
       before do
-        stub_request(:get, 'https://example.com/unknown-status').to_return(status: 200, body: Oj.dump(status_json), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/unknown-status').to_return(status: 200, body: JSON.generate(status_json), headers: { 'Content-Type': 'application/activity+json' })
         quoted_post.update(quote_approval_policy: InteractionPolicy::POLICY_FLAGS[:public] << 16)
       end
 
diff --git a/spec/lib/activitypub/activity_spec.rb b/spec/lib/activitypub/activity_spec.rb
index d7d0700dc6..a4976eb867 100644
--- a/spec/lib/activitypub/activity_spec.rb
+++ b/spec/lib/activitypub/activity_spec.rb
@@ -89,7 +89,7 @@ RSpec.describe ActivityPub::Activity do
     before do
       sender.update(uri: ActivityPub::TagManager.instance.uri_for(sender))
 
-      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump(approval_payload))
+      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate(approval_payload))
     end
 
     context 'when getting them in order' do
diff --git a/spec/lib/activitypub/dereferencer_spec.rb b/spec/lib/activitypub/dereferencer_spec.rb
index 11078de866..13eedf518f 100644
--- a/spec/lib/activitypub/dereferencer_spec.rb
+++ b/spec/lib/activitypub/dereferencer_spec.rb
@@ -12,7 +12,7 @@ RSpec.describe ActivityPub::Dereferencer do
     let(:uri) { nil }
 
     before do
-      stub_request(:get, 'https://example.com/foo').to_return(body: Oj.dump(object), headers: { 'Content-Type' => 'application/activity+json' })
+      stub_request(:get, 'https://example.com/foo').to_return(body: JSON.generate(object), headers: { 'Content-Type' => 'application/activity+json' })
     end
 
     context 'with a URI' do
diff --git a/spec/lib/activitypub/forwarder_spec.rb b/spec/lib/activitypub/forwarder_spec.rb
index f72e334218..7276511a7d 100644
--- a/spec/lib/activitypub/forwarder_spec.rb
+++ b/spec/lib/activitypub/forwarder_spec.rb
@@ -54,8 +54,8 @@ RSpec.describe ActivityPub::Forwarder do
 
     it 'correctly forwards to expected remote followers' do
       expect { subject.forward! }
-        .to enqueue_sidekiq_job(ActivityPub::LowPriorityDeliveryWorker).with(Oj.dump(payload), anything, eve.preferred_inbox_url)
-        .and enqueue_sidekiq_job(ActivityPub::LowPriorityDeliveryWorker).with(Oj.dump(payload), anything, mallory.preferred_inbox_url)
+        .to enqueue_sidekiq_job(ActivityPub::LowPriorityDeliveryWorker).with(JSON.generate(payload), anything, eve.preferred_inbox_url)
+        .and enqueue_sidekiq_job(ActivityPub::LowPriorityDeliveryWorker).with(JSON.generate(payload), anything, mallory.preferred_inbox_url)
     end
   end
 end
diff --git a/spec/lib/webfinger_spec.rb b/spec/lib/webfinger_spec.rb
index e214a03536..7f2251b858 100644
--- a/spec/lib/webfinger_spec.rb
+++ b/spec/lib/webfinger_spec.rb
@@ -10,7 +10,7 @@ RSpec.describe Webfinger do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/activity+json' }] } }
 
       it 'correctly parses the response' do
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
 
         expect(subject.self_link_href).to eq 'https://example.com/alice'
       end
@@ -20,7 +20,7 @@ RSpec.describe Webfinger do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"' }] } }
 
       it 'correctly parses the response' do
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
 
         expect(subject.self_link_href).to eq 'https://example.com/alice'
       end
@@ -30,7 +30,7 @@ RSpec.describe Webfinger do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/json"' }] } }
 
       it 'raises an error' do
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
 
         expect { subject }
           .to raise_error(Webfinger::Error)
@@ -53,7 +53,7 @@ RSpec.describe Webfinger do
 
         before do
           stub_request(:get, 'https://example.com/.well-known/host-meta').to_return(body: host_meta, headers: { 'Content-Type': 'application/jrd+json' })
-          stub_request(:get, 'https://example.com/.well-known/nonStandardWebfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+          stub_request(:get, 'https://example.com/.well-known/nonStandardWebfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
         end
 
         it 'uses host meta details' do
diff --git a/spec/lib/webhooks/payload_renderer_spec.rb b/spec/lib/webhooks/payload_renderer_spec.rb
index 0623edd254..d4a330ea1c 100644
--- a/spec/lib/webhooks/payload_renderer_spec.rb
+++ b/spec/lib/webhooks/payload_renderer_spec.rb
@@ -7,7 +7,7 @@ RSpec.describe Webhooks::PayloadRenderer do
 
   let(:event)   { Webhooks::EventPresenter.new(type, object) }
   let(:payload) { ActiveModelSerializers::SerializableResource.new(event, serializer: REST::Admin::WebhookEventSerializer, scope: nil, scope_name: :current_user).as_json }
-  let(:json)    { Oj.dump(payload) }
+  let(:json)    { JSON.generate(payload) }
 
   describe '#render' do
     context 'when event is account.approved' do
diff --git a/spec/services/activitypub/fetch_featured_collection_service_spec.rb b/spec/services/activitypub/fetch_featured_collection_service_spec.rb
index f0002bc388..24c5fa0a06 100644
--- a/spec/services/activitypub/fetch_featured_collection_service_spec.rb
+++ b/spec/services/activitypub/fetch_featured_collection_service_spec.rb
@@ -75,11 +75,11 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
 
     shared_examples 'sets pinned posts' do
       before do
-        stub_request(:get, 'https://example.com/account/pinned/known').to_return(status: 200, body: Oj.dump(status_json_pinned_known), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/account/pinned/unknown-inlined').to_return(status: 200, body: Oj.dump(status_json_pinned_unknown_inlined), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/account/pinned/known').to_return(status: 200, body: JSON.generate(status_json_pinned_known), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/account/pinned/unknown-inlined').to_return(status: 200, body: JSON.generate(status_json_pinned_unknown_inlined), headers: { 'Content-Type': 'application/activity+json' })
         stub_request(:get, 'https://example.com/account/pinned/unknown-unreachable').to_return(status: 404)
-        stub_request(:get, 'https://example.com/account/pinned/unknown-reachable').to_return(status: 200, body: Oj.dump(status_json_pinned_unknown_reachable), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/account/collections/featured').to_return(status: 200, body: Oj.dump(featured_with_null), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/account/pinned/unknown-reachable').to_return(status: 200, body: JSON.generate(status_json_pinned_unknown_reachable), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/account/collections/featured').to_return(status: 200, body: JSON.generate(featured_with_null), headers: { 'Content-Type': 'application/activity+json' })
 
         subject
       end
@@ -101,7 +101,7 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
         let(:collection_or_uri) { actor.featured_collection_url }
 
         before do
-          stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it_behaves_like 'sets pinned posts'
@@ -122,7 +122,7 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
 
     context 'when the endpoint is a Collection' do
       before do
-        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'sets pinned posts'
@@ -139,7 +139,7 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
       end
 
       before do
-        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'sets pinned posts'
@@ -148,7 +148,7 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
         let(:items) { 'https://example.com/account/pinned/unknown-reachable' }
 
         before do
-          stub_request(:get, 'https://example.com/account/pinned/unknown-reachable').to_return(status: 200, body: Oj.dump(status_json_pinned_unknown_reachable), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, 'https://example.com/account/pinned/unknown-reachable').to_return(status: 200, body: JSON.generate(status_json_pinned_unknown_reachable), headers: { 'Content-Type': 'application/activity+json' })
           subject
         end
 
@@ -175,7 +175,7 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
       end
 
       before do
-        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'sets pinned posts'
@@ -184,7 +184,7 @@ RSpec.describe ActivityPub::FetchFeaturedCollectionService do
         let(:items) { 'https://example.com/account/pinned/unknown-reachable' }
 
         before do
-          stub_request(:get, 'https://example.com/account/pinned/unknown-reachable').to_return(status: 200, body: Oj.dump(status_json_pinned_unknown_reachable), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, 'https://example.com/account/pinned/unknown-reachable').to_return(status: 200, body: JSON.generate(status_json_pinned_unknown_reachable), headers: { 'Content-Type': 'application/activity+json' })
           subject
         end
 
diff --git a/spec/services/activitypub/fetch_featured_tags_collection_service_spec.rb b/spec/services/activitypub/fetch_featured_tags_collection_service_spec.rb
index 59367b1e32..91b5267bdf 100644
--- a/spec/services/activitypub/fetch_featured_tags_collection_service_spec.rb
+++ b/spec/services/activitypub/fetch_featured_tags_collection_service_spec.rb
@@ -38,7 +38,7 @@ RSpec.describe ActivityPub::FetchFeaturedTagsCollectionService do
   describe '#call' do
     context 'when the endpoint is a Collection' do
       before do
-        stub_request(:get, collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'sets featured tags'
@@ -46,7 +46,7 @@ RSpec.describe ActivityPub::FetchFeaturedTagsCollectionService do
 
     context 'when the account already has featured tags' do
       before do
-        stub_request(:get, collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
 
         actor.featured_tags.create!(name: 'FoO')
         actor.featured_tags.create!(name: 'baz')
@@ -67,7 +67,7 @@ RSpec.describe ActivityPub::FetchFeaturedTagsCollectionService do
       end
 
       before do
-        stub_request(:get, collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'sets featured tags'
@@ -88,7 +88,7 @@ RSpec.describe ActivityPub::FetchFeaturedTagsCollectionService do
       end
 
       before do
-        stub_request(:get, collection_url).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_url).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'sets featured tags'
diff --git a/spec/services/activitypub/fetch_remote_account_service_spec.rb b/spec/services/activitypub/fetch_remote_account_service_spec.rb
index 7ebd3cdc70..30d693fa4b 100644
--- a/spec/services/activitypub/fetch_remote_account_service_spec.rb
+++ b/spec/services/activitypub/fetch_remote_account_service_spec.rb
@@ -38,8 +38,8 @@ RSpec.describe ActivityPub::FetchRemoteAccountService do
       before do
         actor[:inbox] = nil
 
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and returns nil' do
@@ -54,8 +54,8 @@ RSpec.describe ActivityPub::FetchRemoteAccountService do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and sets attributes' do
@@ -75,9 +75,9 @@ RSpec.describe ActivityPub::FetchRemoteAccountService do
       let!(:webfinger) { { subject: 'acct:alice@iscool.af', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
-        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and follows redirection and sets attributes' do
@@ -98,8 +98,8 @@ RSpec.describe ActivityPub::FetchRemoteAccountService do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/bob', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and does not create account' do
@@ -114,9 +114,9 @@ RSpec.describe ActivityPub::FetchRemoteAccountService do
       let!(:webfinger) { { subject: 'acct:alice@iscool.af', links: [{ rel: 'self', href: 'https://example.com/bob', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
-        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and follows redirect and does not create account' do
@@ -130,7 +130,7 @@ RSpec.describe ActivityPub::FetchRemoteAccountService do
 
     context 'with wrong id' do
       it 'does not create account' do
-        expect(subject.call('https://fake.address/@foo', prefetched_body: Oj.dump(actor))).to be_nil
+        expect(subject.call('https://fake.address/@foo', prefetched_body: JSON.generate(actor))).to be_nil
       end
     end
   end
diff --git a/spec/services/activitypub/fetch_remote_actor_service_spec.rb b/spec/services/activitypub/fetch_remote_actor_service_spec.rb
index 975e0799dd..36457c207c 100644
--- a/spec/services/activitypub/fetch_remote_actor_service_spec.rb
+++ b/spec/services/activitypub/fetch_remote_actor_service_spec.rb
@@ -38,8 +38,8 @@ RSpec.describe ActivityPub::FetchRemoteActorService do
       before do
         actor[:inbox] = nil
 
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and returns nil' do
@@ -54,8 +54,8 @@ RSpec.describe ActivityPub::FetchRemoteActorService do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and sets values' do
@@ -75,9 +75,9 @@ RSpec.describe ActivityPub::FetchRemoteActorService do
       let!(:webfinger) { { subject: 'acct:alice@iscool.af', links: [{ rel: 'self', href: 'https://example.com/alice', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
-        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and follows redirect and sets values' do
@@ -98,8 +98,8 @@ RSpec.describe ActivityPub::FetchRemoteActorService do
       let!(:webfinger) { { subject: 'acct:alice@example.com', links: [{ rel: 'self', href: 'https://example.com/bob', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and does not create account' do
@@ -114,9 +114,9 @@ RSpec.describe ActivityPub::FetchRemoteActorService do
       let!(:webfinger) { { subject: 'acct:alice@iscool.af', links: [{ rel: 'self', href: 'https://example.com/bob', type: 'application/activity+json' }] } }
 
       before do
-        stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
-        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+        stub_request(:get, 'https://iscool.af/.well-known/webfinger?resource=acct:alice@iscool.af').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       end
 
       it 'fetches resource and looks up webfinger and follows redirect and does not create account' do
@@ -130,7 +130,7 @@ RSpec.describe ActivityPub::FetchRemoteActorService do
 
     context 'with wrong id' do
       it 'does not create account' do
-        expect(subject.call('https://fake.address/@foo', prefetched_body: Oj.dump(actor))).to be_nil
+        expect(subject.call('https://fake.address/@foo', prefetched_body: JSON.generate(actor))).to be_nil
       end
     end
   end
diff --git a/spec/services/activitypub/fetch_remote_key_service_spec.rb b/spec/services/activitypub/fetch_remote_key_service_spec.rb
index ddd1a8067e..635a07c26b 100644
--- a/spec/services/activitypub/fetch_remote_key_service_spec.rb
+++ b/spec/services/activitypub/fetch_remote_key_service_spec.rb
@@ -50,8 +50,8 @@ RSpec.describe ActivityPub::FetchRemoteKeyService do
   end
 
   before do
-    stub_request(:get, 'https://example.com/alice').to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
-    stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+    stub_request(:get, 'https://example.com/alice').to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
+    stub_request(:get, 'https://example.com/.well-known/webfinger?resource=acct:alice@example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
   end
 
   describe '#call' do
@@ -59,7 +59,7 @@ RSpec.describe ActivityPub::FetchRemoteKeyService do
 
     context 'when the key is a sub-object from the actor' do
       before do
-        stub_request(:get, public_key_id).to_return(body: Oj.dump(actor), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, public_key_id).to_return(body: JSON.generate(actor), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it 'returns the expected account' do
@@ -71,7 +71,7 @@ RSpec.describe ActivityPub::FetchRemoteKeyService do
       let(:public_key_id) { 'https://example.com/alice-public-key.json' }
 
       before do
-        stub_request(:get, public_key_id).to_return(body: Oj.dump(key_json.merge({ '@context': ['https://w3id.org/security/v1'] })), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, public_key_id).to_return(body: JSON.generate(key_json.merge({ '@context': ['https://w3id.org/security/v1'] })), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it 'returns the expected account' do
@@ -84,7 +84,7 @@ RSpec.describe ActivityPub::FetchRemoteKeyService do
       let(:actor_public_key) { 'https://example.com/alice-public-key.json' }
 
       before do
-        stub_request(:get, public_key_id).to_return(body: Oj.dump(key_json.merge({ '@context': ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1'] })), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, public_key_id).to_return(body: JSON.generate(key_json.merge({ '@context': ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1'] })), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it 'returns the nil' do
diff --git a/spec/services/activitypub/fetch_remote_status_service_spec.rb b/spec/services/activitypub/fetch_remote_status_service_spec.rb
index 6afee5f25e..e37fcca7a0 100644
--- a/spec/services/activitypub/fetch_remote_status_service_spec.rb
+++ b/spec/services/activitypub/fetch_remote_status_service_spec.rb
@@ -11,7 +11,7 @@ RSpec.describe ActivityPub::FetchRemoteStatusService do
 
   let(:follower) { Fabricate(:account, username: 'alice') }
   let(:follow) { nil }
-  let(:response) { { body: Oj.dump(object), headers: { 'content-type': 'application/activity+json' } } }
+  let(:response) { { body: JSON.generate(object), headers: { 'content-type': 'application/activity+json' } } }
   let(:existing_status) { nil }
 
   let(:note) do
@@ -369,7 +369,7 @@ RSpec.describe ActivityPub::FetchRemoteStatusService do
       end
 
       it 'creates statuses but not more than limit allows' do
-        expect { subject.call(object[:id], prefetched_body: Oj.dump(object)) }
+        expect { subject.call(object[:id], prefetched_body: JSON.generate(object)) }
           .to change { sender.statuses.count }.by_at_least(2)
           .and change { sender.statuses.count }.by_at_most(3)
       end
@@ -419,7 +419,7 @@ RSpec.describe ActivityPub::FetchRemoteStatusService do
       end
 
       it 'creates statuses but not more than limit allows' do
-        expect { subject.call(object[:id], prefetched_body: Oj.dump(object)) }
+        expect { subject.call(object[:id], prefetched_body: JSON.generate(object)) }
           .to change { sender.statuses.count }.by_at_least(2)
           .and change { sender.statuses.count }.by_at_most(3)
       end
diff --git a/spec/services/activitypub/fetch_replies_service_spec.rb b/spec/services/activitypub/fetch_replies_service_spec.rb
index 36159309f1..1442755c53 100644
--- a/spec/services/activitypub/fetch_replies_service_spec.rb
+++ b/spec/services/activitypub/fetch_replies_service_spec.rb
@@ -58,7 +58,7 @@ RSpec.describe ActivityPub::FetchRepliesService do
 
       context 'when passing the URL to the collection' do
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it 'spawns workers for up to 5 replies on the same server' do
@@ -93,7 +93,7 @@ RSpec.describe ActivityPub::FetchRepliesService do
 
       context 'when passing the URL to the collection' do
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it 'spawns workers for up to 5 replies on the same server' do
@@ -132,7 +132,7 @@ RSpec.describe ActivityPub::FetchRepliesService do
 
       context 'when passing the URL to the collection' do
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it 'spawns workers for up to 5 replies on the same server' do
diff --git a/spec/services/activitypub/process_collection_service_spec.rb b/spec/services/activitypub/process_collection_service_spec.rb
index 74df0f9106..cee4272c22 100644
--- a/spec/services/activitypub/process_collection_service_spec.rb
+++ b/spec/services/activitypub/process_collection_service_spec.rb
@@ -21,7 +21,7 @@ RSpec.describe ActivityPub::ProcessCollectionService do
     }
   end
 
-  let(:json) { Oj.dump(payload) }
+  let(:json) { JSON.generate(payload) }
 
   describe '#call' do
     context 'when actor is suspended' do
diff --git a/spec/services/activitypub/process_status_update_service_spec.rb b/spec/services/activitypub/process_status_update_service_spec.rb
index aca2feb008..8279411a33 100644
--- a/spec/services/activitypub/process_status_update_service_spec.rb
+++ b/spec/services/activitypub/process_status_update_service_spec.rb
@@ -23,7 +23,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
       ],
     }
   end
-  let(:json) { Oj.load(Oj.dump(payload)) }
+  let(:json) { Oj.load(JSON.generate(payload)) }
 
   let(:alice) { Fabricate(:account) }
   let(:bob) { Fabricate(:account) }
@@ -545,7 +545,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     end
 
     before do
-      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
         '@context': [
           'https://www.w3.org/ns/activitystreams',
           {
@@ -610,7 +610,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     end
 
     before do
-      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
         '@context': [
           'https://www.w3.org/ns/activitystreams',
           {
@@ -819,7 +819,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     end
 
     before do
-      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
         '@context': [
           'https://www.w3.org/ns/activitystreams',
           {
@@ -884,7 +884,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     end
 
     before do
-      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
         '@context': [
           'https://www.w3.org/ns/activitystreams',
           {
@@ -1127,7 +1127,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     end
 
     before do
-      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+      stub_request(:get, approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
         '@context': [
           'https://www.w3.org/ns/activitystreams',
           {
@@ -1235,7 +1235,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     end
 
     before do
-      stub_request(:get, second_approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+      stub_request(:get, second_approval_uri).to_return(headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
         '@context': [
           'https://www.w3.org/ns/activitystreams',
           {
diff --git a/spec/services/activitypub/synchronize_followers_service_spec.rb b/spec/services/activitypub/synchronize_followers_service_spec.rb
index 813658d149..c41783f7c4 100644
--- a/spec/services/activitypub/synchronize_followers_service_spec.rb
+++ b/spec/services/activitypub/synchronize_followers_service_spec.rb
@@ -55,7 +55,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
 
     context 'when the endpoint is a Collection of actor URIs' do
       before do
-        stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'synchronizes followers'
@@ -72,7 +72,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
       end
 
       before do
-        stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'synchronizes followers'
@@ -93,7 +93,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
       end
 
       before do
-        stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'synchronizes followers'
@@ -102,7 +102,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
     context 'when the endpoint is a paginated Collection of actor URIs split across multiple pages' do
       before do
         stub_request(:get, 'https://example.com/partial-followers')
-          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': 'https://www.w3.org/ns/activitystreams',
             type: 'Collection',
             id: 'https://example.com/partial-followers',
@@ -110,7 +110,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
           }))
 
         stub_request(:get, 'https://example.com/partial-followers/1')
-          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': 'https://www.w3.org/ns/activitystreams',
             type: 'CollectionPage',
             id: 'https://example.com/partial-followers/1',
@@ -120,7 +120,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
           }))
 
         stub_request(:get, 'https://example.com/partial-followers/2')
-          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': 'https://www.w3.org/ns/activitystreams',
             type: 'CollectionPage',
             id: 'https://example.com/partial-followers/2',
@@ -135,7 +135,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
     context 'when the endpoint is a paginated Collection of actor URIs split across, but one page errors out' do
       before do
         stub_request(:get, 'https://example.com/partial-followers')
-          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': 'https://www.w3.org/ns/activitystreams',
             type: 'Collection',
             id: 'https://example.com/partial-followers',
@@ -143,7 +143,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
           }))
 
         stub_request(:get, 'https://example.com/partial-followers/1')
-          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: Oj.dump({
+          .to_return(status: 200, headers: { 'Content-Type': 'application/activity+json' }, body: JSON.generate({
             '@context': 'https://www.w3.org/ns/activitystreams',
             type: 'CollectionPage',
             id: 'https://example.com/partial-followers/1',
@@ -185,7 +185,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
 
       before do
         stub_const('ActivityPub::SynchronizeFollowersService::MAX_COLLECTION_PAGES', 1)
-        stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it 'confirms pending follow request but does not remove extra followers' do
@@ -213,7 +213,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
 
       context 'when the endpoint is a Collection of actor URIs' do
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it_behaves_like 'synchronizes followers'
@@ -230,7 +230,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
         end
 
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it_behaves_like 'synchronizes followers'
@@ -251,7 +251,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
         end
 
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it_behaves_like 'synchronizes followers'
@@ -263,7 +263,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
 
       context 'when the endpoint is a Collection of actor URIs' do
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it 'does not remove followers' do
@@ -286,7 +286,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
         end
 
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it 'does not remove followers' do
@@ -313,7 +313,7 @@ RSpec.describe ActivityPub::SynchronizeFollowersService do
         end
 
         before do
-          stub_request(:get, collection_uri).to_return(status: 200, body: Oj.dump(payload), headers: { 'Content-Type': 'application/activity+json' })
+          stub_request(:get, collection_uri).to_return(status: 200, body: JSON.generate(payload), headers: { 'Content-Type': 'application/activity+json' })
         end
 
         it 'does not remove followers' do
diff --git a/spec/services/activitypub/verify_quote_service_spec.rb b/spec/services/activitypub/verify_quote_service_spec.rb
index 94b9e33ed3..5c9248dbb9 100644
--- a/spec/services/activitypub/verify_quote_service_spec.rb
+++ b/spec/services/activitypub/verify_quote_service_spec.rb
@@ -76,7 +76,7 @@ RSpec.describe ActivityPub::VerifyQuoteService do
 
     before do
       stub_request(:get, approval_uri)
-        .to_return(status: 200, body: Oj.dump(json), headers: { 'Content-Type': 'application/activity+json' })
+        .to_return(status: 200, body: JSON.generate(json), headers: { 'Content-Type': 'application/activity+json' })
     end
 
     context 'with a valid activity for already-fetched posts' do
@@ -179,7 +179,7 @@ RSpec.describe ActivityPub::VerifyQuoteService do
 
     context 'with a valid activity for already-fetched posts, with a pre-fetched approval' do
       it 'updates the status without fetching the activity' do
-        expect { subject.call(quote, prefetched_approval: Oj.dump(json)) }
+        expect { subject.call(quote, prefetched_approval: JSON.generate(json)) }
           .to change(quote, :state).to('accepted')
 
         expect(a_request(:get, approval_uri))
diff --git a/spec/services/fetch_remote_status_service_spec.rb b/spec/services/fetch_remote_status_service_spec.rb
index a9c61e7b4e..2b7ff9cbdc 100644
--- a/spec/services/fetch_remote_status_service_spec.rb
+++ b/spec/services/fetch_remote_status_service_spec.rb
@@ -19,7 +19,7 @@ RSpec.describe FetchRemoteStatusService do
   context 'when protocol is :activitypub' do
     subject { described_class.new.call(note[:id], prefetched_body: prefetched_body) }
 
-    let(:prefetched_body) { Oj.dump(note) }
+    let(:prefetched_body) { JSON.generate(note) }
 
     before do
       subject
diff --git a/spec/services/resolve_account_service_spec.rb b/spec/services/resolve_account_service_spec.rb
index 1bd4e9a8e3..897f7cf44f 100644
--- a/spec/services/resolve_account_service_spec.rb
+++ b/spec/services/resolve_account_service_spec.rb
@@ -103,7 +103,7 @@ RSpec.describe ResolveAccountService do
   context 'with a legitimate webfinger redirection' do
     before do
       webfinger = { subject: 'acct:foo@ap.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
-      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
     end
 
     it 'returns new remote account' do
@@ -121,7 +121,7 @@ RSpec.describe ResolveAccountService do
   context 'with a misconfigured redirection' do
     before do
       webfinger = { subject: 'acct:Foo@redirected.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
-      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
     end
 
     it 'returns new remote account' do
@@ -139,9 +139,9 @@ RSpec.describe ResolveAccountService do
   context 'with too many webfinger redirections' do
     before do
       webfinger = { subject: 'acct:foo@evil.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
-      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: JSON.generate(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
       webfinger2 = { subject: 'acct:foo@ap.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
-      stub_request(:get, 'https://evil.example.com/.well-known/webfinger?resource=acct:foo@evil.example.com').to_return(body: Oj.dump(webfinger2), headers: { 'Content-Type': 'application/jrd+json' })
+      stub_request(:get, 'https://evil.example.com/.well-known/webfinger?resource=acct:foo@evil.example.com').to_return(body: JSON.generate(webfinger2), headers: { 'Content-Type': 'application/jrd+json' })
     end
 
     it 'does not return a new remote account' do
@@ -150,7 +150,7 @@ RSpec.describe ResolveAccountService do
   end
 
   context 'with webfinger response subject missing a host value' do
-    let(:body) { Oj.dump({ subject: 'user@' }) }
+    let(:body) { JSON.generate({ subject: 'user@' }) }
     let(:url) { 'https://host.example/.well-known/webfinger?resource=acct:user@host.example' }
 
     before do
diff --git a/spec/services/software_update_check_service_spec.rb b/spec/services/software_update_check_service_spec.rb
index 73ffe6b899..ac342dce94 100644
--- a/spec/services/software_update_check_service_spec.rb
+++ b/spec/services/software_update_check_service_spec.rb
@@ -82,7 +82,7 @@ RSpec.describe SoftwareUpdateCheckService do
       end
 
       before do
-        stub_request(:get, full_update_check_url).to_return(body: Oj.dump(server_json))
+        stub_request(:get, full_update_check_url).to_return(body: JSON.generate(server_json))
       end
 
       it 'updates the list of known updates' do
diff --git a/spec/support/streaming_client.rb b/spec/support/streaming_client.rb
index 02186e781c..c9a97ab060 100644
--- a/spec/support/streaming_client.rb
+++ b/spec/support/streaming_client.rb
@@ -152,7 +152,7 @@ class StreamingClient
   end
 
   def subscribe(channel, **params)
-    send(Oj.dump({ type: 'subscribe', stream: channel }.merge(params)))
+    send(JSON.generate({ type: 'subscribe', stream: channel }.merge(params)))
   end
 
   def wait_for(event = nil)
diff --git a/spec/workers/activitypub/fetch_all_replies_worker_spec.rb b/spec/workers/activitypub/fetch_all_replies_worker_spec.rb
index 9795c4619a..c7b107ac81 100644
--- a/spec/workers/activitypub/fetch_all_replies_worker_spec.rb
+++ b/spec/workers/activitypub/fetch_all_replies_worker_spec.rb
@@ -126,11 +126,11 @@ RSpec.describe ActivityPub::FetchAllRepliesWorker do
     all_items.each do |item|
       next if [top_note_uri, reply_note_uri].include? item
 
-      stub_request(:get, item).to_return(status: 200, body: Oj.dump(empty_object), headers: { 'Content-Type': 'application/activity+json' })
+      stub_request(:get, item).to_return(status: 200, body: JSON.generate(empty_object), headers: { 'Content-Type': 'application/activity+json' })
     end
 
-    stub_request(:get, top_note_uri).to_return(status: 200, body: Oj.dump(top_object), headers: { 'Content-Type': 'application/activity+json' })
-    stub_request(:get, reply_note_uri).to_return(status: 200, body: Oj.dump(reply_object), headers: { 'Content-Type': 'application/activity+json' })
+    stub_request(:get, top_note_uri).to_return(status: 200, body: JSON.generate(top_object), headers: { 'Content-Type': 'application/activity+json' })
+    stub_request(:get, reply_note_uri).to_return(status: 200, body: JSON.generate(reply_object), headers: { 'Content-Type': 'application/activity+json' })
   end
 
   shared_examples 'fetches all replies' do
@@ -180,8 +180,8 @@ RSpec.describe ActivityPub::FetchAllRepliesWorker do
       end
 
       before do
-        stub_request(:get, top_collection_uri).to_return(status: 200, body: Oj.dump(replies_top), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, reply_collection_uri).to_return(status: 200, body: Oj.dump(replies_nested), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, top_collection_uri).to_return(status: 200, body: JSON.generate(replies_top), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, reply_collection_uri).to_return(status: 200, body: JSON.generate(replies_nested), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'fetches all replies'
@@ -254,8 +254,8 @@ RSpec.describe ActivityPub::FetchAllRepliesWorker do
       end
 
       before do
-        stub_request(:get, top_page_2_uri).to_return(status: 200, body: Oj.dump(top_page_two), headers: { 'Content-Type': 'application/activity+json' })
-        stub_request(:get, reply_page_2_uri).to_return(status: 200, body: Oj.dump(reply_page_two), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, top_page_2_uri).to_return(status: 200, body: JSON.generate(top_page_two), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, reply_page_2_uri).to_return(status: 200, body: JSON.generate(reply_page_two), headers: { 'Content-Type': 'application/activity+json' })
       end
 
       it_behaves_like 'fetches all replies'
diff --git a/spec/workers/activitypub/fetch_replies_worker_spec.rb b/spec/workers/activitypub/fetch_replies_worker_spec.rb
index 56d19705a4..5eea3fcbcf 100644
--- a/spec/workers/activitypub/fetch_replies_worker_spec.rb
+++ b/spec/workers/activitypub/fetch_replies_worker_spec.rb
@@ -17,7 +17,7 @@ RSpec.describe ActivityPub::FetchRepliesWorker do
     }
   end
 
-  let(:json) { Oj.dump(payload) }
+  let(:json) { JSON.generate(payload) }
 
   describe 'perform' do
     it 'performs a request if the collection URI is from the same host' do