diff --git a/lib/redmine/wiki_formatting/common_mark/helper.rb b/lib/redmine/wiki_formatting/common_mark/helper.rb
index 28e2fe10a..cfd2510ed 100644
--- a/lib/redmine/wiki_formatting/common_mark/helper.rb
+++ b/lib/redmine/wiki_formatting/common_mark/helper.rb
@@ -23,13 +23,8 @@ module Redmine
       module Helper
         def wikitoolbar_for(field_id, preview_url = preview_text_path)
           heads_for_wiki_formatter
-          help_file = "/help/#{current_language.to_s.downcase}/wiki_syntax_common_mark.html"
-          # fall back to the english help page if there is none for the current
-          # language
-          unless File.readable? Rails.public_path.join(help_file)
-            help_file = "/help/en/wiki_syntax_common_mark.html"
-          end
-          url = "#{Redmine::Utils.relative_url_root}#{help_file}"
+          url = help_path(current_language)
+
           javascript_tag(
             "var wikiToolbar = new jsToolBar(document.getElementById('#{field_id}')); " \
             "wikiToolbar.setHelpLink('#{escape_javascript url}'); " \
@@ -38,6 +33,16 @@ module Redmine
           )
         end
 
+        def help_path(lang)
+          help_file = "help/#{lang.to_s.downcase}/wiki_syntax_common_mark.html"
+          # fall back to the english help page if there is none for the current
+          # language
+          unless Rails.public_path.join(help_file).readable?
+            help_file = "help/en/wiki_syntax_common_mark.html"
+          end
+          File.join(Redmine::Utils.relative_url_root, help_file)
+        end
+
         def initial_page_content(page)
           "# #{@page.pretty_title}"
         end
diff --git a/test/unit/lib/redmine/wiki_formatting/common_mark/helper_test.rb b/test/unit/lib/redmine/wiki_formatting/common_mark/helper_test.rb
new file mode 100644
index 000000000..e90221529
--- /dev/null
+++ b/test/unit/lib/redmine/wiki_formatting/common_mark/helper_test.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Redmine - project management software
+# Copyright (C) 2006-2023  Jean-Philippe Lang
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+require_relative '../../../../../test_helper'
+
+class Redmine::WikiFormatting::CommonMark::HelperTest < Redmine::HelperTest
+  if Object.const_defined?(:CommonMarker)
+
+    def test_help_path_should_reflect_language
+      assert_equal '/help/de/wiki_syntax_common_mark.html', help_path('de')
+    end
+
+    def test_help_path_should_fallback_to_english
+      assert_equal '/help/en/wiki_syntax_common_mark.html', help_path('xx')
+    end
+  end
+end