diff --git app/helpers/application_helper.rb app/helpers/application_helper.rb
index e2eebfa41..f37e60b03 100644
--- app/helpers/application_helper.rb
+++ app/helpers/application_helper.rb
@@ -1607,7 +1607,7 @@ module ApplicationHelper
   def context_menu
     unless @context_menu_included
       content_for :header_tags do
-        javascript_include_tag('context_menu') +
+        javascript_include_tag('context_menu', type: :module) +
           stylesheet_link_tag('context_menu')
       end
       if l(:direction) == 'rtl'
diff --git public/javascripts/context_menu.js public/javascripts/context_menu.js
index 0dd6ad6b9..2c5886364 100644
--- public/javascripts/context_menu.js
+++ public/javascripts/context_menu.js
@@ -1,23 +1,23 @@
 /* Redmine - project management software
    Copyright (C) 2006-2022  Jean-Philippe Lang */
 
-var contextMenuObserving;
+var observing;
 
-function contextMenuRightClick(event) {
+function rightClick(event) {
   var target = $(event.target);
   if (target.is('a:not(.js-contextmenu)')) {return;}
   var tr = target.closest('.hascontextmenu').first();
   if (tr.length < 1) {return;}
   event.preventDefault();
-  if (!contextMenuIsSelected(tr)) {
-    contextMenuUnselectAll();
-    contextMenuAddSelection(tr);
-    contextMenuSetLastSelected(tr);
+  if (!isSelected(tr)) {
+    unselectAll();
+    addSelection(tr);
+    setLastSelected(tr);
   }
-  contextMenuShow(event);
+  show(event);
 }
 
-function contextMenuClick(event) {
+function click(event) {
   var target = $(event.target);
   var lastSelected;
 
@@ -25,7 +25,7 @@ function contextMenuClick(event) {
     event.preventDefault();
     return;
   }
-  contextMenuHide();
+  hide();
   if (target.is('a') || target.is('img')) { return; }
   if (event.which == 1 || (navigator.appVersion.match(/\bMSIE\b/))) {
     var tr = target.closest('.hascontextmenu').first();
@@ -45,29 +45,29 @@ function contextMenuClick(event) {
         }
       } else {
         if (event.ctrlKey || event.metaKey) {
-          contextMenuToggleSelection(tr);
-          contextMenuClearDocumentSelection();
+          toggleSelection(tr);
+          clearDocumentSelection();
         } else if (event.shiftKey) {
-          lastSelected = contextMenuLastSelected();
+          lastSelected = getLastSelected();
           if (lastSelected.length) {
             var toggling = false;
             $('.hascontextmenu').each(function(){
               if (toggling || $(this).is(tr)) {
-                contextMenuAddSelection($(this));
-                contextMenuClearDocumentSelection();
+                addSelection($(this));
+                clearDocumentSelection();
               }
               if ($(this).is(tr) || $(this).is(lastSelected)) {
                 toggling = !toggling;
               }
             });
           } else {
-            contextMenuAddSelection(tr);
+            addSelection(tr);
           }
         } else {
-          contextMenuUnselectAll();
-          contextMenuAddSelection(tr);
+          unselectAll();
+          addSelection(tr);
         }
-        contextMenuSetLastSelected(tr);
+        setLastSelected(tr);
       }
     } else {
       // click is outside the rows
@@ -76,13 +76,13 @@ function contextMenuClick(event) {
       } else if (target.is('.toggle-selection') || target.is('.ui-dialog *') || $('#ajax-modal').is(':visible')) {
         // nop
       } else {
-        contextMenuUnselectAll();
+        unselectAll();
       }
     }
   }
 }
 
-function contextMenuCreate() {
+function create() {
   if ($('#context-menu').length < 1) {
     var menu = document.createElement("div");
     menu.setAttribute("id", "context-menu");
@@ -91,7 +91,7 @@ function contextMenuCreate() {
   }
 }
 
-function contextMenuShow(event) {
+function show(event) {
   var mouse_x = event.pageX;
   var mouse_y = event.pageY;  
   var mouse_y_c = event.clientY;  
@@ -161,54 +161,54 @@ function contextMenuShow(event) {
   });
 }
 
-function contextMenuSetLastSelected(tr) {
+function setLastSelected(tr) {
   $('.cm-last').removeClass('cm-last');
   tr.addClass('cm-last');
 }
 
-function contextMenuLastSelected() {
+function getLastSelected() {
   return $('.cm-last').first();
 }
 
-function contextMenuUnselectAll() {
+function unselectAll() {
   $('input[type=checkbox].toggle-selection').prop('checked', false);
   $('.hascontextmenu').each(function(){
-    contextMenuRemoveSelection($(this));
+    removeSelection($(this));
   });
   $('.cm-last').removeClass('cm-last');
 }
 
-function contextMenuHide() {
+function hide() {
   $('#context-menu').hide();
 }
 
-function contextMenuToggleSelection(tr) {
-  if (contextMenuIsSelected(tr)) {
-    contextMenuRemoveSelection(tr);
+function toggleSelection(tr) {
+  if (isSelected(tr)) {
+    removeSelection(tr);
   } else {
-    contextMenuAddSelection(tr);
+    addSelection(tr);
   }
 }
 
-function contextMenuAddSelection(tr) {
+function addSelection(tr) {
   tr.addClass('context-menu-selection');
-  contextMenuCheckSelectionBox(tr, true);
+  checkSelectionBox(tr, true);
 }
 
-function contextMenuRemoveSelection(tr) {
+function removeSelection(tr) {
   tr.removeClass('context-menu-selection');
-  contextMenuCheckSelectionBox(tr, false);
+  checkSelectionBox(tr, false);
 }
 
-function contextMenuIsSelected(tr) {
+function isSelected(tr) {
   return tr.hasClass('context-menu-selection');
 }
 
-function contextMenuCheckSelectionBox(tr, checked) {
+function checkSelectionBox(tr, checked) {
   tr.find('input[type=checkbox]').prop('checked', checked);
 }
 
-function contextMenuClearDocumentSelection() {
+function clearDocumentSelection() {
   // TODO
   if (document.selection) {
     document.selection.empty(); // IE
@@ -217,15 +217,15 @@ function contextMenuClearDocumentSelection() {
   }
 }
 
-function contextMenuInit() {
-  contextMenuCreate();
-  contextMenuUnselectAll();
+function init() {
+  create();
+  unselectAll();
   
-  if (!contextMenuObserving) {
-    $(document).click(contextMenuClick);
-    $(document).contextmenu(contextMenuRightClick);
-    $(document).on('click', '.js-contextmenu', contextMenuRightClick);
-    contextMenuObserving = true;
+  if (!observing) {
+    $(document).click(click);
+    $(document).contextmenu(rightClick);
+    $(document).on('click', '.js-contextmenu', rightClick);
+    observing = true;
   }
 }
 
@@ -252,6 +252,6 @@ function window_size() {
 }
 
 $(document).ready(function(){
-  contextMenuInit();
+  init();
   $('input[type=checkbox].toggle-selection').on('change', toggleIssuesSelection);
 });