--- a/plugins/redmine_workload/lib/redmine_workload.rb
+++ b/plugins/redmine_workload/lib/redmine_workload.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require_relative 'redmine_workload/extensions/user_patch'
-require_relative 'redmine_workload/hooks/plugin'
+require_relative 'redmine_workload/hooks/after_plugins_loaded_hook'
 require_relative 'redmine_workload/group_workload_preparer'
 require_relative 'redmine_workload/user_workload_preparer'
 require_relative 'redmine_workload/wl_calculation_restrictions'
--- a/plugins/redmine_workload/lib/redmine_workload/group_workload_preparer.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/group_workload_preparer.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 require 'forwardable'
 
 class GroupWorkloadPreparer
@@ -44,3 +46,5 @@ class GroupWorkloadPreparer
 
   attr_writer :data, :params
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/user_workload_preparer.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/user_workload_preparer.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 require 'forwardable'
 
 class UserWorkloadPreparer
@@ -36,3 +38,5 @@ class UserWorkloadPreparer
 
   attr_writer :data, :params
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_calculation_restrictions.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_calculation_restrictions.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 module WlCalculationRestrictions
   def consider_parent_issues?
     settings['workload_of_parent_issues'].present?
@@ -9,3 +11,5 @@ module WlCalculationRestrictions
     Setting.plugin_redmine_workload
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_csv_exporter.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_csv_exporter.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 require 'forwardable'
 
 class WlCsvExporter
@@ -32,7 +34,7 @@ class WlCsvExporter
     return unless data
 
     klass = data.class
-    "#{klass}Preparer".constantize.new(data: data, params: params)
+    "RedmineWorkload::#{klass}Preparer".constantize.new(data: data, params: params)
   end
 
   def planned_line(assignee, workload)
@@ -106,3 +108,5 @@ class WlCsvExporter
     data.time_span.map { |date| format_date(date) }
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_date_tools.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_date_tools.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 require_relative 'wl_user_data_defaults'
 
 class WlDateTools
@@ -85,3 +87,5 @@ class WlDateTools
     !WlUserVacation.where('user_id = ? AND date_from <= ? AND date_to >= ?', assignee.id, day, day).empty?
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_issue_query.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_issue_query.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 module WlIssueQuery
   include WlCalculationRestrictions
   ##
@@ -38,3 +40,5 @@ module WlIssueQuery
     issues.split.flatten
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_issue_state.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_issue_state.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 module WlIssueState
   ##
   # Redefines the overdue state of an issue. Instead of comparing issue.due_date
@@ -10,3 +12,5 @@ module WlIssueState
     issue.due_date.present? && (issue.due_date < date) && !issue.closed?
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_user_data_defaults.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_user_data_defaults.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 ##
 # Provides the default values for WlUserData object
 #
@@ -14,3 +16,5 @@ module WlUserDataDefaults
     Setting['plugin_redmine_workload']
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/lib/redmine_workload/wl_user_data_finder.rb
+++ b/plugins/redmine_workload/lib/redmine_workload/wl_user_data_finder.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+module RedmineWorkload
+
 ##
 # Finder method for WLUserData
 #
@@ -14,3 +16,5 @@ module WlUserDataFinder
     @user_workload_data
   end
 end
+
+end
\ No newline at end of file
--- a/plugins/redmine_workload/app/controllers/wl_national_holiday_controller.rb
+++ b/plugins/redmine_workload/app/controllers/wl_national_holiday_controller.rb
@@ -3,7 +3,7 @@
 require 'json'
 
 class WlNationalHolidayController < ApplicationController
-  include WlUserDataFinder
+  include RedmineWorkload::WlUserDataFinder
 
   before_action :authorize_global, only: %i[create update destroy]
   before_action :find_user_workload_data
--- a/plugins/redmine_workload/app/controllers/wl_user_datas_controller.rb
+++ b/plugins/redmine_workload/app/controllers/wl_user_datas_controller.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class WlUserDatasController < ApplicationController
-  include WlUserDataFinder
+  include RedmineWorkload::WlUserDataFinder
 
   helper :workloads
   helper :wl_user_datas
--- a/plugins/redmine_workload/app/controllers/wl_user_vacations_controller.rb
+++ b/plugins/redmine_workload/app/controllers/wl_user_vacations_controller.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class WlUserVacationsController < ApplicationController
-  include WlUserDataFinder
+  include RedmineWorkload::WlUserDataFinder
 
   helper :workloads
 
--- a/plugins/redmine_workload/app/controllers/workloads_controller.rb
+++ b/plugins/redmine_workload/app/controllers/workloads_controller.rb
@@ -11,7 +11,7 @@ class WorkloadsController < ApplicationController
   helper :workloads
 
   include QueriesHelper
-  include WlUserDataFinder
+  include RedmineWorkload::WlUserDataFinder
   include WorkloadsHelper
 
   before_action :authorize_global, only: %i[index]
@@ -40,7 +40,7 @@ class WorkloadsController < ApplicationController
                                        time_span: @time_span_to_display,
                                        today: @today)
 
-      @months_to_render = WlDateTools.months_in_time_span(@time_span_to_display)
+      @months_to_render = RedmineWorkload::WlDateTools.months_in_time_span(@time_span_to_display)
       @workload_data = user_workload.hours_per_user_issue_and_day
 
       @group_workload = GroupWorkload.new(users: @users,
--- a/plugins/redmine_workload/app/models/group_workload.rb
+++ b/plugins/redmine_workload/app/models/group_workload.rb
@@ -72,7 +72,7 @@ class GroupWorkload
   end
 
   def total_availabilities_of(user)
-    working_days = WlDateTools.working_days_in_time_span(time_span, user)
+    working_days = RedmineWorkload::WlDateTools.working_days_in_time_span(time_span, user)
     time_span.each_with_object({}) do |day, hash|
       holiday = working_days.exclude?(day)
       capacity = WlDayCapacity.new(assignee: user)
--- a/plugins/redmine_workload/app/models/user_workload.rb
+++ b/plugins/redmine_workload/app/models/user_workload.rb
@@ -6,8 +6,8 @@
 #
 class UserWorkload
   include Redmine::I18n
-  include WlIssueQuery
-  include WlIssueState
+  include RedmineWorkload::WlIssueQuery
+  include RedmineWorkload::WlIssueState
 
   attr_reader :assignees, :issues, :time_span, :today
 
@@ -225,7 +225,7 @@ class UserWorkload
         }
       end
 
-      first_working_day_after_today = WlDateTools.working_days_in_time_span(today..time_span.end, assignee).min
+      first_working_day_after_today = RedmineWorkload::WlDateTools.working_days_in_time_span(today..time_span.end, assignee).min
       result[first_working_day_after_today] = {} if result[first_working_day_after_today].nil?
       result[first_working_day_after_today][:hours] = hours_remaining
 
@@ -271,7 +271,7 @@ class UserWorkload
     else
       # Number of remaining working days for the issue:
       remaining_time_span = [today, issue.start_date].max..issue.due_date
-      number_of_workdays_for_issue = WlDateTools.real_distance_in_days(remaining_time_span, assignee)
+      number_of_workdays_for_issue = RedmineWorkload::WlDateTools.real_distance_in_days(remaining_time_span, assignee)
       hours_per_workday = hours_remaining / number_of_workdays_for_issue.to_f
 
       time_span.each do |day|
@@ -356,7 +356,7 @@ class UserWorkload
   # Collects all working days within a given time span.
   #
   def working_days_in_time_span(assignee:, no_cache: false)
-    WlDateTools.working_days_in_time_span(time_span, assignee, no_cache: no_cache)
+    RedmineWorkload::WlDateTools.working_days_in_time_span(time_span, assignee, no_cache: no_cache)
   end
 
   ##
--- a/plugins/redmine_workload/app/models/wl_default_user_data.rb
+++ b/plugins/redmine_workload/app/models/wl_default_user_data.rb
@@ -4,7 +4,7 @@
 # Holds default user related data for workload calculation.
 #
 class WlDefaultUserData
-  include WlUserDataDefaults
+  include RedmineWorkload::WlUserDataDefaults
 
   def threshold_lowload_min
     default_attributes[:threshold_lowload_min].to_f
--- a/plugins/redmine_workload/app/models/wl_user_data.rb
+++ b/plugins/redmine_workload/app/models/wl_user_data.rb
@@ -4,7 +4,7 @@
 # Holds user related data for workload calculation.
 #
 class WlUserData < ActiveRecord::Base
-  include WlUserDataDefaults
+  include RedmineWorkload::WlUserDataDefaults
 
   belongs_to :user, inverse_of: :wl_user_data, optional: true
   self.table_name = 'wl_user_datas'
--- a/plugins/redmine_workload/app/helpers/workloads_helper.rb
+++ b/plugins/redmine_workload/app/helpers/workloads_helper.rb
@@ -88,7 +88,7 @@ module WorkloadsHelper
   end
 
   def workloads_to_csv(workload, params)
-    prepare = WlCsvExporter.new(data: workload, params: params)
+    prepare = RedmineWorkload::WlCsvExporter.new(data: workload, params: params)
     Redmine::Export::CSV.generate(encoding: params[:encoding]) do |csv|
       csv << prepare.header_fields
       prepare.group_workload.each do |level, data|
--- a/plugins/redmine_workload/test/unit/group_user_dummy_test.rb
+++ b/plugins/redmine_workload/test/unit/group_user_dummy_test.rb
@@ -3,7 +3,7 @@
 require File.expand_path('../test_helper', __dir__)
 
 class GroupUserDummyTest < ActiveSupport::TestCase
-  include WlUserDataFinder
+  include RedmineWorkload::WlUserDataFinder
   include WorkloadsHelper
 
   fixtures :trackers, :projects, :projects_trackers, :members, :member_roles,
--- a/plugins/redmine_workload/test/unit/user_selection_test.rb
+++ b/plugins/redmine_workload/test/unit/user_selection_test.rb
@@ -3,7 +3,7 @@
 require File.expand_path('../test_helper', __dir__)
 
 class WlUserSelectionTest < ActiveSupport::TestCase
-  include WlUserDataDefaults
+  include RedmineWorkload::WlUserDataDefaults
 
   fixtures :trackers, :projects, :projects_trackers, :members, :member_roles,
            :users, :issue_statuses, :enumerations, :roles
--- a/plugins/redmine_workload/test/unit/user_workload_test.rb
+++ b/plugins/redmine_workload/test/unit/user_workload_test.rb
@@ -5,7 +5,7 @@ require File.expand_path('../test_helper', __dir__)
 class UserWorkloadTest < ActiveSupport::TestCase
   include RedmineWorkload::WorkloadObjectHelper
   include WorkloadsHelper
-  include WlUserDataDefaults
+  include RedmineWorkload::WlUserDataDefaults
 
   fixtures :trackers, :projects, :projects_trackers, :members, :member_roles,
            :users, :issue_statuses, :enumerations, :roles
--- a/plugins/redmine_workload/test/unit/wl_national_holiday_test.rb
+++ b/plugins/redmine_workload/test/unit/wl_national_holiday_test.rb
@@ -22,7 +22,7 @@ class WlNationalHolidayTest < ActiveSupport::TestCase
                                     reason: 'Test Holiday')
 
     assert holiday.save, 'Holiday could not be created or saved!'
-    assert WlDateTools.holiday?(holiday[:start]), '2017-05-30 should be a holiday!'
+    assert RedmineWorkload::WlDateTools.holiday?(holiday[:start]), '2017-05-30 should be a holiday!'
     assert holiday.destroy, 'Holiday could not be deleted!'
   end
 
@@ -32,8 +32,8 @@ class WlNationalHolidayTest < ActiveSupport::TestCase
     holiday.save
 
     assert holiday.save, 'Holiday could not be created or saved!'
-    assert WlDateTools.holiday?(holiday[:start]), '2017-05-30 should be a holiday!'
-    assert WlDateTools.holiday?(holiday[:end]), '2017-05-31 should be a holiday!'
+    assert RedmineWorkload::WlDateTools.holiday?(holiday[:start]), '2017-05-30 should be a holiday!'
+    assert RedmineWorkload::WlDateTools.holiday?(holiday[:end]), '2017-05-31 should be a holiday!'
   end
 
   test 'holiday is not workday' do
@@ -60,7 +60,7 @@ class WlNationalHolidayTest < ActiveSupport::TestCase
     holiday1.save
     holiday2.save
 
-    result = WlDateTools.working_days_in_time_span(first_day..last_day, user).to_a
+    result = RedmineWorkload::WlDateTools.working_days_in_time_span(first_day..last_day, user).to_a
 
     assert_equal [first_day, last_day - 1], result, 'Result should only bring 2 workdays!'
 
--- a/plugins/redmine_workload/test/unit/wl_user_vacation_test.rb
+++ b/plugins/redmine_workload/test/unit/wl_user_vacation_test.rb
@@ -42,7 +42,7 @@ class WlUserVacationTest < ActiveSupport::TestCase
 
     vac1.save
 
-    assert WlDateTools::vacation?(day, user1), 'User should have Vacation!'
+    assert RedmineWorkload::WlDateTools::vacation?(day, user1), 'User should have Vacation!'
   end
 
   test 'vacation should not be in working days' do
@@ -59,7 +59,7 @@ class WlUserVacationTest < ActiveSupport::TestCase
     firstDay = Date.new(2017, 5, 29)
     lastDay = Date.new(2017, 6, 1)
 
-    result = WlDateTools.working_days_in_time_span(firstDay..lastDay, user1)
+    result = RedmineWorkload::WlDateTools.working_days_in_time_span(firstDay..lastDay, user1)
 
     assert_equal [firstDay, lastDay], result.to_a, 'Result should only bring 2 workdays!'
   end
--- a/plugins/redmine_workload/test/unit/wl_csv_exporter_test.rb
+++ b/plugins/redmine_workload/test/unit/wl_csv_exporter_test.rb
@@ -5,7 +5,7 @@ require File.expand_path('../test_helper', __dir__)
 class WlCsvExporterTest < ActiveSupport::TestCase
 
   def setup 
-    @exporter = WlCsvExporter.new(data: nil, params: {})
+    @exporter = RedmineWorkload::WlCsvExporter.new(data: nil, params: {})
   end
 
   test 'should respond to data' do
@@ -22,11 +22,11 @@ class WlCsvExporterTest < ActiveSupport::TestCase
 
   test 'should initialize UserWorkloadPreparer object' do
     data = UserWorkload.new(assignees: [], time_span: 1..5, today: Time.zone.today)
-    assert_equal 'UserWorkloadPreparer', @exporter.send(:initialize_data_object, data).class.name
+    assert_equal 'RedmineWorkload::UserWorkloadPreparer', @exporter.send(:initialize_data_object, data).class.name
   end
 
   test 'should initialize GroupWorkloadPreparer object' do
     data = GroupWorkload.new(users: WlUserSelection.new, user_workload: {}, time_span: 1..5)
-    assert_equal 'GroupWorkloadPreparer', @exporter.send(:initialize_data_object, data).class.name
+    assert_equal 'RedmineWorkload::GroupWorkloadPreparer', @exporter.send(:initialize_data_object, data).class.name
   end
 end
--- a/plugins/redmine_workload/test/unit/user_workload_preparer_test.rb
+++ b/plugins/redmine_workload/test/unit/user_workload_preparer_test.rb
@@ -6,22 +6,22 @@ class UserWorkloadPreparerTest < ActiveSupport::TestCase
   include Redmine::I18n
 
   test 'should respond to user_workload' do
-    preparer = UserWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::UserWorkloadPreparer.new(data: {}, params: {})
     assert preparer.respond_to? :user_workload
   end
 
   test 'should repsond to time_span' do
-    preparer = UserWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::UserWorkloadPreparer.new(data: {}, params: {})
     assert preparer.respond_to? :time_span
   end
 
   test 'should repsond to group_workload' do
-    preparer = UserWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::UserWorkloadPreparer.new(data: {}, params: {})
     assert preparer.respond_to? :group_workload
   end
 
   test 'should return type of assignee' do
-    preparer = UserWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::UserWorkloadPreparer.new(data: {}, params: {})
     assert_equal 'User', preparer.type(User.generate!)
   end
 
@@ -30,7 +30,7 @@ class UserWorkloadPreparerTest < ActiveSupport::TestCase
     user = User.generate!
     user.groups << group
     user.create_wl_user_data(main_group: group.id)
-    preparer = UserWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::UserWorkloadPreparer.new(data: {}, params: {})
     assert_equal group.name, preparer.main_group(user)
   end
 end
--- a/plugins/redmine_workload/test/unit/group_workload_preparer_test.rb
+++ b/plugins/redmine_workload/test/unit/group_workload_preparer_test.rb
@@ -6,22 +6,22 @@ class GroupWorkloadPreparerTest < ActiveSupport::TestCase
   include Redmine::I18n
 
   test 'should respond to user_workload' do
-    preparer = GroupWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::GroupWorkloadPreparer.new(data: {}, params: {})
     assert preparer.respond_to? :user_workload
   end
 
   test 'should repsond to time_span' do
-    preparer = GroupWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::GroupWorkloadPreparer.new(data: {}, params: {})
     assert preparer.respond_to? :time_span
   end
 
   test 'should repsond to group_workload' do
-    preparer = GroupWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::GroupWorkloadPreparer.new(data: {}, params: {})
     assert preparer.respond_to? :group_workload
   end
 
   test 'should return type of assignee' do
-    preparer = GroupWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::GroupWorkloadPreparer.new(data: {}, params: {})
     assert_equal l(:label_aggregation), preparer.type(Group.generate!)
     assert_equal 'User', preparer.type(User.generate!)
   end
@@ -32,7 +32,7 @@ class GroupWorkloadPreparerTest < ActiveSupport::TestCase
     user = User.generate!
     user.groups << group
     user.create_wl_user_data(main_group: group.id)
-    preparer = GroupWorkloadPreparer.new(data: {}, params: {})
+    preparer = RedmineWorkload::GroupWorkloadPreparer.new(data: {}, params: {})
     assert_equal group.name, preparer.main_group(user)
     assert_equal dummy.main_group.name, preparer.main_group(dummy)
   end
--- a/plugins/redmine_workload/test/unit/wl_date_tools_test.rb
+++ b/plugins/redmine_workload/test/unit/wl_date_tools_test.rb
@@ -14,7 +14,7 @@ class WlDateToolsTest < ActiveSupport::TestCase
     Setting['plugin_redmine_workload']['general_workday_friday'] = 'checked'
 
     date = Date.new(2005, 12, 30) # A friday
-    assert_equal Set.new([date]), WlDateTools.working_days_in_time_span(date..date, @user, no_cache: true)
+    assert_equal Set.new([date]), RedmineWorkload::WlDateTools.working_days_in_time_span(date..date, @user, no_cache: true)
   end
 
   test 'working_days_in_time_span works if start and end day are equal and a holiday.' do
@@ -22,13 +22,13 @@ class WlDateToolsTest < ActiveSupport::TestCase
     Setting['plugin_redmine_workload']['general_workday_friday'] = ''
 
     date = Date.new(2005, 12, 30) # A friday
-    assert_equal Set.new, WlDateTools.working_days_in_time_span(date..date, @user, no_cache: true)
+    assert_equal Set.new, RedmineWorkload::WlDateTools.working_days_in_time_span(date..date, @user, no_cache: true)
   end
 
   test 'working_days_in_time_span works if start day before end day.' do
     start_date = Date.new(2005, 12, 30) # A friday
     end_date = Date.new(2005, 12, 28) # A wednesday
-    assert_equal Set.new, WlDateTools.working_days_in_time_span(start_date..end_date, @user, no_cache: true)
+    assert_equal Set.new, RedmineWorkload::WlDateTools.working_days_in_time_span(start_date..end_date, @user, no_cache: true)
   end
 
   test 'working_days_in_time_span works if both days follow each other and are holidays.' do
@@ -38,7 +38,7 @@ class WlDateToolsTest < ActiveSupport::TestCase
 
     start_date = Date.new(2005, 12, 28) # A wednesday
     end_date = Date.new(2005, 12, 29) # A thursday
-    assert_equal Set.new, WlDateTools.working_days_in_time_span(start_date..end_date, @user, no_cache: true)
+    assert_equal Set.new, RedmineWorkload::WlDateTools.working_days_in_time_span(start_date..end_date, @user, no_cache: true)
   end
 
   test 'working_days_in_time_span works if only weekends and mondays are holidays and startday is thursday, endday is tuesday.' do
@@ -60,7 +60,7 @@ class WlDateToolsTest < ActiveSupport::TestCase
       end_date
     ]
 
-    assert_equal Set.new(expected_result), WlDateTools.working_days_in_time_span(start_date..end_date, @user, no_cache: true)
+    assert_equal Set.new(expected_result), RedmineWorkload::WlDateTools.working_days_in_time_span(start_date..end_date, @user, no_cache: true)
   end
 
   test 'working_days returns the working days.' do
@@ -73,14 +73,14 @@ class WlDateToolsTest < ActiveSupport::TestCase
     Setting['plugin_redmine_workload']['general_workday_saturday'] = ''
     Setting['plugin_redmine_workload']['general_workday_sunday'] = ''
 
-    assert_equal Set.new([2, 3, 4, 5]), WlDateTools.working_days
+    assert_equal Set.new([2, 3, 4, 5]), RedmineWorkload::WlDateTools.working_days
   end
 
   test 'getMonthsBetween returns [] if last day after first day' do
     first_day = Date.new(2012, 3, 29)
     last_day = Date.new(2012, 3, 28)
 
-    assert_equal [], WlDateTools.months_in_time_span(first_day..last_day)
+    assert_equal [], RedmineWorkload::WlDateTools.months_in_time_span(first_day..last_day)
   end
 
   test 'getMonthsBetween returns [3] if both days in march 2012 and equal' do
@@ -124,14 +124,14 @@ class WlDateToolsTest < ActiveSupport::TestCase
     user1, user2 = users_defined
     user1.wl_user_vacations.create(date_from: first_day, date_to: first_day)
     user2.wl_user_vacations.create(date_from: last_day, date_to: last_day)
-    assert WlDateTools.vacation?(first_day, user1)
-    assert_not WlDateTools.vacation?(first_day, user2)
+    assert RedmineWorkload::WlDateTools.vacation?(first_day, user1)
+    assert_not RedmineWorkload::WlDateTools.vacation?(first_day, user2)
   end
 
   private
 
   def months_numbers_in_time_span(first_day, last_day)
-    WlDateTools.months_in_time_span(first_day..last_day).map do |span|
+    RedmineWorkload::WlDateTools.months_in_time_span(first_day..last_day).map do |span|
       [span[:first_day].month, span[:last_day].month]
     end
   end
--- a/plugins/redmine_workload/test/unit/lib/wl_issue_query_test.rb
+++ b/plugins/redmine_workload/test/unit/lib/wl_issue_query_test.rb
@@ -4,7 +4,7 @@ require File.expand_path('../../test_helper', __dir__)
 
 class WlIssueQueryTest < ActiveSupport::TestCase
   include RedmineWorkload::WorkloadObjectHelper
-  include WlIssueQuery
+  include RedmineWorkload::WlIssueQuery
 
   fixtures :trackers, :projects, :projects_trackers, :members, :member_roles,
            :users, :issue_statuses, :enumerations, :roles
--- a/plugins/redmine_workload/test/functional/wl_user_datas_controller_test.rb
+++ b/plugins/redmine_workload/test/functional/wl_user_datas_controller_test.rb
@@ -4,7 +4,7 @@ require File.expand_path('../test_helper', __dir__)
 
 class WlUserDatasControllerTest < ActionDispatch::IntegrationTest
   include RedmineWorkload::AuthenticateUser
-  include WlUserDataFinder
+  include RedmineWorkload::WlUserDataFinder
 
   fixtures :trackers, :projects, :projects_trackers, :members, :member_roles,
            :users, :issue_statuses, :enumerations, :roles
