diff --git a/Rakefile b/Rakefile
index 3bc1b563e1..7dca66359d 100644
--- a/Rakefile
+++ b/Rakefile
@@ -4,8 +4,13 @@ require "bundler"
 require "bundler/gem_tasks"
 Bundler.setup
 
+ROOT = File.expand_path(File.join(File.dirname(__FILE__)))
+
+$: << File.join(ROOT, 'spec/shared/lib')
+
 require "rake"
 require "rspec/core/rake_task"
+require 'mrss/spec_organizer'
 
 $LOAD_PATH.unshift File.expand_path("../lib", __FILE__)
 require "mongoid/version"
@@ -38,11 +43,30 @@ RSpec::Core::RakeTask.new('spec:progress') do |spec|
   spec.pattern = "spec/**/*_spec.rb"
 end
 
-task :ci do
-  $LOAD_PATH.push File.expand_path("../spec", __FILE__)
-  require 'support/spec_organizer'
+CLASSIFIERS = [
+  [%r,^mongoid/attribute,, :attributes],
+  [%r,^mongoid/association/[or],, :associations_referenced],
+  [%r,^mongoid/association,, :associations],
+  [%r,^mongoid,, :unit],
+  [%r,^integration,, :integration],
+  [%r,^rails,, :rails],
+]
+
+RUN_PRIORITY = %i(
+  unit attributes associations_referenced associations
+  integration rails
+)
+
+def spec_organizer
+  Mrss::SpecOrganizer.new(
+    root: ROOT,
+    classifiers: CLASSIFIERS,
+    priority_order: RUN_PRIORITY,
+  )
+end
 
-  SpecOrganizer.new.run
+task :ci do
+  spec_organizer.run
 end
 
 task :default => :spec
diff --git a/spec/integration/app_spec.rb b/spec/integration/app_spec.rb
index 946b0258d7..1e7fc8236d 100644
--- a/spec/integration/app_spec.rb
+++ b/spec/integration/app_spec.rb
@@ -13,7 +13,7 @@
     end
 
     require 'fileutils'
-    require 'support/child_process_helper'
+    require 'mrss/child_process_helper'
     require 'open-uri'
 
     FileUtils.mkdir_p(TMP_BASE)
@@ -91,19 +91,19 @@
     ['~> 5.1.0', '~> 5.2.0', '~> 6.0.0'].each do |rails_version|
       context "with rails #{rails_version}" do
         it 'creates' do
-          ChildProcessHelper.check_call(%w(gem uni rails -a))
-          ChildProcessHelper.check_call(%w(gem install rails --no-document -v) + [rails_version])
+          Mrss::ChildProcessHelper.check_call(%w(gem uni rails -a))
+          Mrss::ChildProcessHelper.check_call(%w(gem install rails --no-document -v) + [rails_version])
 
           Dir.chdir(TMP_BASE) do
             FileUtils.rm_rf('mongoid-test')
-            ChildProcessHelper.check_call(%w(rails new mongoid-test --skip-spring --skip-active-record), env: clean_env)
+            Mrss::ChildProcessHelper.check_call(%w(rails new mongoid-test --skip-spring --skip-active-record), env: clean_env)
 
             Dir.chdir('mongoid-test') do
               adjust_app_gemfile
-              ChildProcessHelper.check_call(%w(bundle install), env: clean_env)
+              Mrss::ChildProcessHelper.check_call(%w(bundle install), env: clean_env)
 
-              ChildProcessHelper.check_call(%w(rails g model post), env: clean_env)
-              ChildProcessHelper.check_call(%w(rails g model comment post:belongs_to), env: clean_env)
+              Mrss::ChildProcessHelper.check_call(%w(rails g model post), env: clean_env)
+              Mrss::ChildProcessHelper.check_call(%w(rails g model comment post:belongs_to), env: clean_env)
 
               # https://jira.mongodb.org/browse/MONGOID-4885
               comment_text = File.read('app/models/comment.rb')
@@ -136,7 +136,7 @@
               before do
                 Dir.chdir(APP_PATH) do
                   remove_bundler_req
-                  ChildProcessHelper.check_call(%w(bundle install), env: env)
+                  Mrss::ChildProcessHelper.check_call(%w(bundle install), env: env)
                   write_mongoid_yml
                 end
 
@@ -150,7 +150,7 @@
                 end
                 index.should be nil
 
-                ChildProcessHelper.check_call(%w(rake db:mongoid:create_indexes),
+                Mrss::ChildProcessHelper.check_call(%w(rake db:mongoid:create_indexes),
                   cwd: APP_PATH, env: env)
 
                 index = client['posts'].indexes.detect do |index|
@@ -168,10 +168,10 @@
   def clone_application(repo_url, subdir: nil, rails_version: nil)
     Dir.chdir(TMP_BASE) do
       FileUtils.rm_rf(File.basename(repo_url))
-      ChildProcessHelper.check_call(%w(git clone) + [repo_url])
+      Mrss::ChildProcessHelper.check_call(%w(git clone) + [repo_url])
       Dir.chdir(File.join(*[File.basename(repo_url), subdir].compact)) do
         adjust_app_gemfile(rails_version: rails_version)
-        ChildProcessHelper.check_call(%w(bundle install), env: clean_env)
+        Mrss::ChildProcessHelper.check_call(%w(bundle install), env: clean_env)
         puts `git diff`
 
         write_mongoid_yml
@@ -230,7 +230,7 @@ def remove_spring
     # in `initialize': too long unix socket path (126bytes given but 108bytes max) (ArgumentError)
     # Is it trying to create unix sockets in current directory?
     # https://stackoverflow.com/questions/30302021/rails-runner-without-spring
-    ChildProcessHelper.check_call(%w(bin/spring binstub --remove --all), env: clean_env)
+    Mrss::ChildProcessHelper.check_call(%w(bin/spring binstub --remove --all), env: clean_env)
   end
 
   def clean_env
diff --git a/spec/shared b/spec/shared
index 2d1d703bff..8cc5a3f702 160000
--- a/spec/shared
+++ b/spec/shared
@@ -1 +1 @@
-Subproject commit 2d1d703bff613f891460359d8b15f6a0256dd14f
+Subproject commit 8cc5a3f70266166fef21c60ffb5bc5b3dcd1a7c9
diff --git a/spec/support/child_process_helper.rb b/spec/support/child_process_helper.rb
deleted file mode 100644
index ec23f8c9bb..0000000000
--- a/spec/support/child_process_helper.rb
+++ /dev/null
@@ -1,79 +0,0 @@
-# frozen_string_literal: true
-# encoding: utf-8
-
-gem 'childprocess'
-require 'childprocess'
-require 'tempfile'
-
-module ChildProcessHelper
-  class SpawnError < StandardError; end
-
-  module_function def call(cmd, env: nil, cwd: nil)
-    process = ChildProcess.new(*cmd)
-    process.io.inherit!
-    if cwd
-      process.cwd = cwd
-    end
-    if env
-      env.each do |k, v|
-        process.environment[k.to_s] = v
-      end
-    end
-    process.start
-    process.wait
-    process
-  end
-
-  module_function def check_call(cmd, env: nil, cwd: nil)
-    process = call(cmd, env: env, cwd: cwd)
-    unless process.exit_code == 0
-      raise "Failed to execute: #{cmd}"
-    end
-  end
-
-  module_function def get_output(cmd, env: nil, cwd: nil)
-    process = ChildProcess.new(*cmd)
-    process.io.inherit!
-    if cwd
-      process.cwd = cwd
-    end
-    if env
-      env.each do |k, v|
-        process.environment[k.to_s] = v
-      end
-    end
-
-    output = ''
-    r, w = IO.pipe
-
-    begin
-      process.io.stdout = w
-      process.start
-      w.close
-
-      thread = Thread.new do
-        begin
-          loop do
-            output << r.readpartial(16384)
-          end
-        rescue EOFError
-        end
-      end
-
-      process.wait
-      thread.join
-    ensure
-      r.close
-    end
-
-    [process, output]
-  end
-
-  module_function def check_output(*args)
-    process, output = get_output(*args)
-    unless process.exit_code == 0
-      raise "Failed to execute: #{args}"
-    end
-    output
-  end
-end
diff --git a/spec/support/spec_organizer.rb b/spec/support/spec_organizer.rb
deleted file mode 100644
index 17a8d3cea6..0000000000
--- a/spec/support/spec_organizer.rb
+++ /dev/null
@@ -1,130 +0,0 @@
-require 'support/child_process_helper'
-require 'json'
-
-autoload :FileUtils, 'fileutils'
-autoload :Find, 'find'
-
-# Organizes and runs all of the tests in the test suite in batches.
-#
-# Organizing the tests in batches serves two purposes:
-#
-# 1. This allows running unit tests before integration tests, therefore
-#    in theory revealing failures quicker on average.
-# 2. This allows running some tests that have high intermittent failure rate
-#    in their own test process.
-#
-# This class aggregates RSpec results after the test runs.
-class SpecOrganizer
-  CLASSIFIERS = [
-    [%r,^mongoid/attribute,, :attributes],
-    [%r,^mongoid/association/[or],, :associations_referenced],
-    [%r,^mongoid/association,, :associations],
-    [%r,^mongoid,, :unit],
-    [%r,^integration,, :integration],
-    [%r,^rails,, :rails],
-  ]
-
-  RUN_PRIORITY = %i(
-    unit attributes associations_referenced associations
-    integration rails
-  )
-
-  SPEC_ROOT = File.expand_path(File.join(File.dirname(__FILE__), '..'))
-  ROOT = File.expand_path(File.join(SPEC_ROOT, '..'))
-  RSPEC_JSON_PATH = File.join(ROOT, 'tmp/rspec.json')
-  RSPEC_ALL_JSON_PATH = File.join(ROOT, 'tmp/rspec-all.json')
-
-  def run
-    FileUtils.rm_f(RSPEC_ALL_JSON_PATH)
-
-    buckets = {}
-    Find.find(SPEC_ROOT) do |path|
-      next unless File.file?(path)
-      next unless path =~ /_spec\.rb\z/
-      rel_path = path[(SPEC_ROOT.length + 1)..path.length]
-
-      found = false
-      CLASSIFIERS.each do |(regexp, category)|
-        if regexp =~ rel_path
-          buckets[category] ||= []
-          buckets[category] << rel_path
-          found = true
-          break
-        end
-      end
-
-      unless found
-        buckets[nil] ||= []
-        buckets[nil] << rel_path
-      end
-    end
-
-    failed = []
-
-    RUN_PRIORITY.each do |category|
-      if files = buckets.delete(category)
-        unless run_files(category, files)
-          failed << category
-        end
-      end
-    end
-    if files = buckets.delete(nil)
-      unless run_files('remaining', files)
-        failed << 'remaining'
-      end
-    end
-
-    unless buckets.empty?
-      raise "Some buckets were not executed: #{buckets.keys.map(&:to_s).join(', ')}"
-    end
-
-    if failed.any?
-      raise "The following buckets failed: #{failed.map(&:to_s).join(', ')}"
-    end
-  end
-
-  def run_files(category, paths)
-    paths = paths.map do |path|
-      File.join('spec', path)
-    end
-
-    puts "Running #{category.to_s.gsub('_', ' ')} tests"
-    FileUtils.rm_f(RSPEC_JSON_PATH)
-    cmd = %w(rspec) + paths
-
-    begin
-      ChildProcessHelper.check_call(cmd)
-    ensure
-      if File.exist?(RSPEC_JSON_PATH)
-        if File.exist?(RSPEC_ALL_JSON_PATH)
-          merge_rspec_results
-        else
-          FileUtils.cp(RSPEC_JSON_PATH, RSPEC_ALL_JSON_PATH)
-        end
-      end
-    end
-
-    true
-  rescue ChildProcessHelper::SpawnError
-    false
-  end
-
-  def merge_rspec_results
-    all = JSON.parse(File.read(RSPEC_ALL_JSON_PATH))
-    new = JSON.parse(File.read(RSPEC_JSON_PATH))
-    all['examples'] += new.delete('examples')
-    new.delete('summary').each do |k, v|
-      all['summary'][k] += v
-    end
-    new.delete('version')
-    new.delete('summary_line')
-    unless new.empty?
-      raise "Unhandled rspec results keys: #{new.keys.join(', ')}"
-    end
-    # We do not merge summary lines, delete them from aggregated results
-    all.delete('summary_line')
-    File.open(RSPEC_ALL_JSON_PATH, 'w') do |f|
-      f << JSON.dump(all)
-    end
-  end
-end