diff --git a/script/build/test_slice_tests.sh b/script/build/test_slice_tests.sh
index cd4919851..8da4c701d 100755
--- a/script/build/test_slice_tests.sh
+++ b/script/build/test_slice_tests.sh
@@ -12,7 +12,6 @@ if [ "$LEVEL" == '1' ]; then
   cp test/integration/aaa_auto_wizard_base_setup_test.rb test/browser/aaa_auto_wizard_base_setup_test.rb
   rm test/browser/abb_one_group_test.rb
   rm test/browser/admin_channel_email_test.rb
-  rm test/browser/admin_calendar_sla_test.rb
   rm test/browser/admin_drag_drop_to_new_group_test.rb
   rm test/browser/admin_overview_test.rb
   rm test/browser/admin_permissions_granular_vs_full_test.rb
@@ -72,7 +71,6 @@ elif [ "$LEVEL" == '2' ]; then
   # test/browser/aaa_getting_started_test.rb
   # test/browser/abb_one_group_test.rb
   rm test/browser/admin_channel_email_test.rb
-  rm test/browser/admin_calendar_sla_test.rb
   rm test/browser/admin_drag_drop_to_new_group_test.rb
   rm test/browser/admin_overview_test.rb
   rm test/browser/admin_permissions_granular_vs_full_test.rb
@@ -132,7 +130,6 @@ elif [ "$LEVEL" == '3' ]; then
   # test/browser/aaa_getting_started_test.rb
   # test/browser/abb_one_group_test.rb
   rm test/browser/admin_channel_email_test.rb
-  rm test/browser/admin_calendar_sla_test.rb
   rm test/browser/admin_drag_drop_to_new_group_test.rb
   rm test/browser/admin_overview_test.rb
   rm test/browser/admin_permissions_granular_vs_full_test.rb
@@ -192,7 +189,6 @@ elif [ "$LEVEL" == '4' ]; then
   # test/browser/aaa_getting_started_test.rb
   # test/browser/abb_one_group_test.rb
   rm test/browser/admin_channel_email_test.rb
-  rm test/browser/admin_calendar_sla_test.rb
   rm test/browser/admin_drag_drop_to_new_group_test.rb
   rm test/browser/admin_overview_test.rb
   rm test/browser/admin_permissions_granular_vs_full_test.rb
@@ -251,7 +247,6 @@ elif [ "$LEVEL" == '5' ]; then
   # only profile action & admin
   # test/browser/abb_one_group_test.rb
   # test/browser/admin_channel_email_test.rb
-  # test/browser/admin_calendar_sla_test.rb
   # rm test/browser/admin_drag_drop_to_new_group_test.rb
   # test/browser/admin_overview_test.rb
   # rm test/browser/admin_permissions_granular_vs_full_test.rb
@@ -313,7 +308,6 @@ elif [ "$LEVEL" == '6' ]; then
   cp test/integration/aaa_auto_wizard_base_setup_test.rb test/browser/aaa_auto_wizard_base_setup_test.rb
   rm test/browser/abb_one_group_test.rb
   rm test/browser/admin_channel_email_test.rb
-  rm test/browser/admin_calendar_sla_test.rb
   rm test/browser/admin_drag_drop_to_new_group_test.rb
   rm test/browser/admin_overview_test.rb
   rm test/browser/admin_permissions_granular_vs_full_test.rb
diff --git a/spec/system/manage/sla_spec.rb b/spec/system/manage/sla_spec.rb
index e667856ef..385109e81 100644
--- a/spec/system/manage/sla_spec.rb
+++ b/spec/system/manage/sla_spec.rb
@@ -57,4 +57,23 @@ RSpec.describe 'Manage > Sla', type: :system do
       expect(page.find('input[name=solution_time_in_text]')[:required]).not_to eq('true')
     end
   end
+
+  context 'when using custom calendars' do
+    let(:calendar) { create(:calendar) }
+
+    it 'allows to select custom calendars' do
+      calendar
+      page.refresh
+      click '.js-new'
+
+      within '.modal-dialog' do
+        fill_in :name, with: 'SLA with custom calendar'
+        select calendar.name, from: :calendar_id
+        click '.js-submit'
+      end
+
+      modal_disappear
+      expect(page).to have_text(calendar.name)
+    end
+  end
 end
diff --git a/test/browser/admin_calendar_sla_test.rb b/test/browser/admin_calendar_sla_test.rb
deleted file mode 100644
index 8f0580aa2..000000000
--- a/test/browser/admin_calendar_sla_test.rb
+++ /dev/null
@@ -1,85 +0,0 @@
-# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
-
-require 'browser_test_helper'
-
-class AdminCalendarSlaTest < TestCase
-  def test_calendar
-    @browser = browser_instance
-    login(
-      username: 'admin@example.com',
-      password: 'test',
-      url:      browser_url,
-    )
-    tasks_close_all
-
-    calendar_name = "ZZZ some calendar #{SecureRandom.uuid}"
-    sla_name = "ZZZ some sla #{SecureRandom.uuid}"
-    timezone = 'Europe/Berlin'
-    timezone_verify = "Europe/Berlin\s\\(GMT\\+(2|1)\\)"
-    calendar_create(
-      data: {
-        name:     calendar_name,
-        timezone: timezone,
-      }
-    )
-
-    # got to maintanance
-    click(css: '[href="#manage"]')
-    click(css: '[href="#system/maintenance"]')
-    watch_for(
-      css:     '.content.active',
-      value:   'Enable or disable the maintenance mode',
-      timeout: 4,
-    )
-
-    # go back
-    click(css: '[href="#manage"]')
-    click(css: '[href="#manage/calendars"]')
-    watch_for(
-      css:     '.content.active',
-      value:   calendar_name,
-      timeout: 4,
-    )
-
-    logout
-
-    login(
-      username: 'admin@example.com',
-      password: 'test',
-    )
-
-    # check if admin exists
-    click(css: '[href="#manage"]')
-    click(css: '[href="#manage/calendars"]')
-    watch_for(
-      css:     '.content.active',
-      value:   calendar_name,
-      timeout: 4,
-    )
-
-    # @browser.execute_script('$(\'.content.active table tr td:contains(" ' + data[:name] + '")\').first().click()')
-    @browser.execute_script('$(\'.content.active .main .js-edit\').last().click()')
-
-    modal_ready(browser: @browser)
-    watch_for(
-      css:     '.content.active .modal input[name=name]',
-      value:   calendar_name,
-      timeout: 4,
-    )
-    watch_for(
-      css:     '.content.active .modal input.js-input',
-      value:   timezone_verify,
-      timeout: 4,
-    )
-    modal_close
-
-    sla_create(
-      data: {
-        name:                        sla_name,
-        calendar:                    "#{calendar_name} - #{timezone}",
-        first_response_time_in_text: 61
-      },
-    )
-
-  end
-end