diff --git a/src/node/hooks/express/static.js b/src/node/hooks/express/static.js
index 26c18995a..7c8426cc3 100644
--- a/src/node/hooks/express/static.js
+++ b/src/node/hooks/express/static.js
@@ -1,15 +1,113 @@
 'use strict';
 
-const fs = require('fs').promises;
 const minify = require('../../utils/Minify');
-const path = require('path');
 const plugins = require('../../../static/js/pluginfw/plugin_defs');
 const settings = require('../../utils/Settings');
 const CachingMiddleware = require('../../utils/caching_middleware');
 const Yajsml = require('etherpad-yajsml');
 
-// Rewrite tar to include modules with no extensions and proper rooted paths.
-const getTar = async () => {
+const tar = (() => {
+  const associations = {
+    'pad.js': [
+      'pad.js',
+      'pad_utils.js',
+      '$js-cookie/dist/js.cookie.js',
+      'security.js',
+      '$security.js',
+      'vendors/browser.js',
+      'pad_cookie.js',
+      'pad_editor.js',
+      'pad_editbar.js',
+      'vendors/nice-select.js',
+      'pad_modals.js',
+      'pad_automatic_reconnect.js',
+      'ace.js',
+      'collab_client.js',
+      'cssmanager.js',
+      'pad_userlist.js',
+      'pad_impexp.js',
+      'pad_savedrevs.js',
+      'pad_connectionstatus.js',
+      'ChatMessage.js',
+      'chat.js',
+      'vendors/gritter.js',
+      '$js-cookie/dist/js.cookie.js',
+      '$tinycon/tinycon.js',
+      'vendors/farbtastic.js',
+      'skin_variants.js',
+      'socketio.js',
+      'colorutils.js',
+    ],
+    'timeslider.js': [
+      'timeslider.js',
+      'colorutils.js',
+      'draggable.js',
+      'pad_utils.js',
+      '$js-cookie/dist/js.cookie.js',
+      'vendors/browser.js',
+      'pad_cookie.js',
+      'pad_editor.js',
+      'pad_editbar.js',
+      'vendors/nice-select.js',
+      'pad_modals.js',
+      'pad_automatic_reconnect.js',
+      'pad_savedrevs.js',
+      'pad_impexp.js',
+      'AttributePool.js',
+      'Changeset.js',
+      'domline.js',
+      'linestylefilter.js',
+      'cssmanager.js',
+      'broadcast.js',
+      'broadcast_slider.js',
+      'broadcast_revisions.js',
+      'socketio.js',
+      'AttributeManager.js',
+      'AttributeMap.js',
+      'attributes.js',
+      'ChangesetUtils.js',
+    ],
+    'ace2_inner.js': [
+      'ace2_inner.js',
+      'vendors/browser.js',
+      'AttributePool.js',
+      'Changeset.js',
+      'ChangesetUtils.js',
+      'skiplist.js',
+      'colorutils.js',
+      'undomodule.js',
+      '$unorm/lib/unorm.js',
+      'contentcollector.js',
+      'changesettracker.js',
+      'linestylefilter.js',
+      'domline.js',
+      'AttributeManager.js',
+      'AttributeMap.js',
+      'attributes.js',
+      'scroll.js',
+      'caretPosition.js',
+      'pad_utils.js',
+      '$js-cookie/dist/js.cookie.js',
+      'security.js',
+      '$security.js',
+    ],
+    'ace2_common.js': [
+      'ace2_common.js',
+      'vendors/browser.js',
+      'vendors/jquery.js',
+      'rjquery.js',
+      '$async.js',
+      'underscore.js',
+      '$underscore.js',
+      '$underscore/underscore.js',
+      'security.js',
+      '$security.js',
+      'pluginfw/client_plugins.js',
+      'pluginfw/plugin_defs.js',
+      'pluginfw/shared.js',
+      'pluginfw/hooks.js',
+    ],
+  };
   const prefixLocalLibraryPath = (path) => {
     if (path.charAt(0) === '$') {
       return path.slice(1);
@@ -17,16 +115,15 @@ const getTar = async () => {
       return `ep_etherpad-lite/static/js/${path}`;
     }
   };
-  const tarJson = await fs.readFile(path.join(settings.root, 'src/node/utils/tar.json'), 'utf8');
   const tar = {};
-  for (const [key, relativeFiles] of Object.entries(JSON.parse(tarJson))) {
+  for (const [key, relativeFiles] of Object.entries(associations)) {
     const files = relativeFiles.map(prefixLocalLibraryPath);
     tar[prefixLocalLibraryPath(key)] = files
         .concat(files.map((p) => p.replace(/\.js$/, '')))
         .concat(files.map((p) => `${p.replace(/\.js$/, '')}/index.js`));
   }
   return tar;
-};
+})();
 
 exports.expressPreSession = async (hookName, {app}) => {
   // Cache both minified and static.
@@ -49,7 +146,7 @@ exports.expressPreSession = async (hookName, {app}) => {
   });
 
   const StaticAssociator = Yajsml.associators.StaticAssociator;
-  const associations = Yajsml.associators.associationsForSimpleMapping(await getTar());
+  const associations = Yajsml.associators.associationsForSimpleMapping(tar);
   const associator = new StaticAssociator(associations);
   jsServer.setAssociator(associator);
 
diff --git a/src/node/utils/tar.json b/src/node/utils/tar.json
deleted file mode 100644
index 08ae93f6b..000000000
--- a/src/node/utils/tar.json
+++ /dev/null
@@ -1,101 +0,0 @@
-{
-  "pad.js": [
-    "pad.js"
-  , "pad_utils.js"
-  , "$js-cookie/dist/js.cookie.js"
-  , "security.js"
-  , "$security.js"
-  , "vendors/browser.js"
-  , "pad_cookie.js"
-  , "pad_editor.js"
-  , "pad_editbar.js"
-  , "vendors/nice-select.js"
-  , "pad_modals.js"
-  , "pad_automatic_reconnect.js"
-  , "ace.js"
-  , "collab_client.js"
-  , "cssmanager.js"
-  , "pad_userlist.js"
-  , "pad_impexp.js"
-  , "pad_savedrevs.js"
-  , "pad_connectionstatus.js"
-  , "ChatMessage.js"
-  , "chat.js"
-  , "vendors/gritter.js"
-  , "$js-cookie/dist/js.cookie.js"
-  , "$tinycon/tinycon.js"
-  , "vendors/farbtastic.js"
-  , "skin_variants.js"
-  , "socketio.js"
-  , "colorutils.js"
-  ]
-, "timeslider.js": [
-    "timeslider.js"
-  , "colorutils.js"
-  , "draggable.js"
-  , "pad_utils.js"
-  , "$js-cookie/dist/js.cookie.js"
-  , "vendors/browser.js"
-  , "pad_cookie.js"
-  , "pad_editor.js"
-  , "pad_editbar.js"
-  , "vendors/nice-select.js"
-  , "pad_modals.js"
-  , "pad_automatic_reconnect.js"
-  , "pad_savedrevs.js"
-  , "pad_impexp.js"
-  , "AttributePool.js"
-  , "Changeset.js"
-  , "domline.js"
-  , "linestylefilter.js"
-  , "cssmanager.js"
-  , "broadcast.js"
-  , "broadcast_slider.js"
-  , "broadcast_revisions.js"
-  , "socketio.js"
-  , "AttributeManager.js"
-  , "AttributeMap.js"
-  , "attributes.js"
-  , "ChangesetUtils.js"
-  ]
-, "ace2_inner.js": [
-    "ace2_inner.js"
-  , "vendors/browser.js"
-  , "AttributePool.js"
-  , "Changeset.js"
-  , "ChangesetUtils.js"
-  , "skiplist.js"
-  , "colorutils.js"
-  , "undomodule.js"
-  , "$unorm/lib/unorm.js"
-  , "contentcollector.js"
-  , "changesettracker.js"
-  , "linestylefilter.js"
-  , "domline.js"
-  , "AttributeManager.js"
-  , "AttributeMap.js"
-  , "attributes.js"
-  , "scroll.js"
-  , "caretPosition.js"
-  , "pad_utils.js"
-  , "$js-cookie/dist/js.cookie.js"
-  , "security.js"
-  , "$security.js"
-  ]
-, "ace2_common.js": [
-    "ace2_common.js"
-  , "vendors/browser.js"
-  , "vendors/jquery.js"
-  , "rjquery.js"
-  , "$async.js"
-  , "underscore.js"
-  , "$underscore.js"
-  , "$underscore/underscore.js"
-  , "security.js"
-  , "$security.js"
-  , "pluginfw/client_plugins.js"
-  , "pluginfw/plugin_defs.js"
-  , "pluginfw/shared.js"
-  , "pluginfw/hooks.js"
-  ]
-}
diff --git a/src/tests/backend/specs/caching_middleware.js b/src/tests/backend/specs/caching_middleware.js
index ebfd65d9f..34e5585bd 100644
--- a/src/tests/backend/specs/caching_middleware.js
+++ b/src/tests/backend/specs/caching_middleware.js
@@ -1,9 +1,8 @@
 'use strict';
 
 /**
- * caching_middleware is responsible for serving everything under path `/javascripts/`
- * That includes packages as defined in `src/node/utils/tar.json` and probably also plugin code
- *
+ * caching_middleware is responsible for serving everything under path `/javascripts/`. That
+ * includes packages as defined in `src/node/hooks/express/static.js` and probably also plugin code.
  */
 
 const common = require('../common');