diff --git a/Gemfile b/Gemfile
index c9e74455a..15f2af41c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -41,7 +41,7 @@ gem 'omniauth-cas', '~> 1.1'
 gem 'omniauth-saml', '~> 1.10'
 gem 'omniauth', '~> 1.2'
 
-gem 'doorkeeper', '~> 4.4'
+gem 'doorkeeper', '~> 5.0'
 gem 'fast_blank', '~> 1.0'
 gem 'fastimage'
 gem 'goldfinger', '~> 2.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index 2da3fe324..945c0776e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -181,7 +181,7 @@ GEM
     docile (1.3.0)
     domain_name (0.5.20180417)
       unf (>= 0.0.5, < 1.0.0)
-    doorkeeper (4.4.2)
+    doorkeeper (5.0.0)
       railties (>= 4.2)
     dotenv (2.2.2)
     dotenv-rails (2.2.2)
@@ -670,7 +670,7 @@ DEPENDENCIES
   devise (~> 4.4)
   devise-two-factor (~> 3.0)
   devise_pam_authenticatable2 (~> 9.1)
-  doorkeeper (~> 4.4)
+  doorkeeper (~> 5.0)
   dotenv-rails (~> 2.2, < 2.3)
   fabrication (~> 2.20)
   faker (~> 1.8)
diff --git a/app/services/activitypub/fetch_remote_account_service.rb b/app/services/activitypub/fetch_remote_account_service.rb
index 6fa4e9a1b..1ec9ee5dd 100644
--- a/app/services/activitypub/fetch_remote_account_service.rb
+++ b/app/services/activitypub/fetch_remote_account_service.rb
@@ -7,14 +7,14 @@ class ActivityPub::FetchRemoteAccountService < BaseService
 
   # Should be called when uri has already been checked for locality
   # Does a WebFinger roundtrip on each call
-  def call(uri, id: true, prefetched_body: nil)
+  def call(uri, id: true, prefetched_body: nil, break_on_redirect: false)
     @json = if prefetched_body.nil?
               fetch_resource(uri, id)
             else
               body_to_json(prefetched_body, compare_id: id ? uri : nil)
             end
 
-    return unless supported_context? && expected_type?
+    return if !supported_context? || !expected_type? || (break_on_redirect && @json['movedTo'].present?)
 
     @uri      = @json['id']
     @username = @json['preferredUsername']
diff --git a/app/services/activitypub/process_account_service.rb b/app/services/activitypub/process_account_service.rb
index 453253db4..7f95678b0 100644
--- a/app/services/activitypub/process_account_service.rb
+++ b/app/services/activitypub/process_account_service.rb
@@ -175,7 +175,7 @@ class ActivityPub::ProcessAccountService < BaseService
 
   def moved_account
     account   = ActivityPub::TagManager.instance.uri_to_resource(@json['movedTo'], Account)
-    account ||= ActivityPub::FetchRemoteAccountService.new.call(@json['movedTo'], id: true)
+    account ||= ActivityPub::FetchRemoteAccountService.new.call(@json['movedTo'], id: true, break_on_redirect: true)
     account
   end
 
diff --git a/db/migrate/20180514140000_revert_index_change_on_statuses_for_api_v1_accounts_account_id_statuses.rb b/db/migrate/20180514140000_revert_index_change_on_statuses_for_api_v1_accounts_account_id_statuses.rb
index 4a8761fec..ccd2ec7ea 100644
--- a/db/migrate/20180514140000_revert_index_change_on_statuses_for_api_v1_accounts_account_id_statuses.rb
+++ b/db/migrate/20180514140000_revert_index_change_on_statuses_for_api_v1_accounts_account_id_statuses.rb
@@ -5,7 +5,7 @@ class RevertIndexChangeOnStatusesForApiV1AccountsAccountIdStatuses < ActiveRecor
 
   def change
     safety_assured do
-      add_index :statuses, [:account_id, :id, :visibility, :updated_at], order: { id: :desc }, algorithm: :concurrently, name: :index_statuses_20180106 unless index_exists?(:statuses, name: "index_statuses_20180106")
+      add_index :statuses, [:account_id, :id, :visibility, :updated_at], order: { id: :desc }, algorithm: :concurrently, name: :index_statuses_20180106 unless index_name_exists?(:statuses, "index_statuses_20180106")
     end
 
     # These index may not exists (see migration 20180514130000)
diff --git a/db/migrate/20180528141303_fix_accounts_unique_index.rb b/db/migrate/20180528141303_fix_accounts_unique_index.rb
index 96cee37f9..bd4e158b7 100644
--- a/db/migrate/20180528141303_fix_accounts_unique_index.rb
+++ b/db/migrate/20180528141303_fix_accounts_unique_index.rb
@@ -1,4 +1,17 @@
 class FixAccountsUniqueIndex < ActiveRecord::Migration[5.2]
+  class Account < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    has_one :user, inverse_of: :account
+
+    def local?
+      domain.nil?
+    end
+
+    def acct
+      local? ? username : "#{username}@#{domain}"
+    end
+  end
+
   disable_ddl_transaction!
 
   def up
diff --git a/lib/mastodon/version.rb b/lib/mastodon/version.rb
index 87099675b..38debbd6e 100644
--- a/lib/mastodon/version.rb
+++ b/lib/mastodon/version.rb
@@ -13,7 +13,7 @@ module Mastodon
     end
 
     def patch
-      4
+      5
     end
 
     def pre