diff --git a/Makefile b/Makefile
index 5383c36..a2c4b31 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 .PHONY: node_deps clean_dist deps clean_deps lit_localize_extract lit_localize_build lit_localize_all serve_chromium_mv3 serve_gecko release release_chromium_stable release_chromium_beta release_chromium_canary release_gecko_stable build_test_extension clean_releases test clean trigger_nightly_build
 
 WEBPACK := ./node_modules/webpack-cli/bin/cli.js
-JEST := node --experimental-vm-modules ./node_modules/jest/bin/jest.js
+JEST := node ./node_modules/jest/bin/jest.js
 RELEASE_SCRIPT := bash tools/release.bash
 
 grpc_proto_gen:
diff --git a/jest.config.js b/jest.config.js
index b394077..c468c76 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -4,7 +4,7 @@
  */
 
 module.exports = {
-  preset : 'ts-jest/presets/js-with-ts-esm',
+  preset : 'ts-jest/presets/js-with-ts',
   moduleFileExtensions : ['js', 'mjs', 'ts'],
   testRegex : '(/__tests__/.*|(\\.|/)(test|spec))\\.m?[jt]sx?$',
   coverageProvider : 'v8',
diff --git a/roles/test/tasks/main.yaml b/roles/test/tasks/main.yaml
index 8430fc7..80d0848 100644
--- a/roles/test/tasks/main.yaml
+++ b/roles/test/tasks/main.yaml
@@ -2,7 +2,7 @@
   shell:
     cmd: |
       set -euxo pipefail
-      node --experimental-vm-modules ./node_modules/jest/bin/jest.js --ci |& tee out/jest-log.txt
+      node ./node_modules/jest/bin/jest.js --ci |& tee out/jest-log.txt
     chdir: "{{ zuul.project.src_dir }}"
     executable: /bin/bash
   changed_when: false
diff --git a/src/common/protojs.test.mjs b/src/common/protojs.test.mjs
deleted file mode 100644
index b5ee44c..0000000
--- a/src/common/protojs.test.mjs
+++ /dev/null
@@ -1,148 +0,0 @@
-/* eslint-disable no-sparse-arrays */
-import * as protojs from './protojs.js';
-
-const objectLike1 = {
-  '2': [1, 2, 3],
-};
-
-const arrayLike1 = [
-  undefined,
-  [1, 2, 3],
-];
-
-const rObjectLike1 = [
-  ,
-  undefined,
-  [, 1, 2, 3],
-];
-
-const objectLike2 = {
-  '1': {
-    '1': 12,
-    '2': [
-      {
-        '6': [false, false, false],
-        '7': {
-          '1': false,
-          '2': 'Hola',
-        },
-      },
-      {
-        '6': [true, true, false],
-        '7': {
-          '1': false,
-          '2': 'Test',
-        },
-      },
-      {
-        '6': [],
-        '7': {
-          '1': true,
-          '2': 'Bye',
-        },
-      },
-    ],
-    '3': 1663,
-  },
-};
-
-const arrayLike2 = [[
-  12,
-  [
-    [
-      undefined, undefined, undefined, undefined, undefined,
-      [false, false, false],
-      [
-        false,
-        'Hola',
-      ]
-    ],
-    [
-      undefined, undefined, undefined, undefined, undefined,
-      [true, true, false],
-      [
-        false,
-        'Test',
-      ]
-    ],
-    [
-      undefined, undefined, undefined, undefined, undefined, [],
-      [
-        true,
-        'Bye',
-      ]
-    ],
-  ],
-  1663,
-]];
-
-const rObjectLike2 = [, [
-  ,
-  12,
-  [
-    ,
-    [
-      , undefined, undefined, undefined, undefined, undefined,
-      [, false, false, false],
-      [
-        ,
-        false,
-        'Hola',
-      ]
-    ],
-    [
-      , undefined, undefined, undefined, undefined, undefined,
-      [, true, true, false],
-      [
-        ,
-        false,
-        'Test',
-      ]
-    ],
-    [
-      , undefined, undefined, undefined, undefined, undefined, [],
-      [
-        ,
-        true,
-        'Bye',
-      ]
-    ],
-  ],
-  1663,
-]];
-
-test('can convert object-like to array-like', () => {
-  // [ object-like input, array-like verified output ]
-  const entries = [
-    [objectLike1, arrayLike1],
-    [rObjectLike1, arrayLike1],
-    [objectLike2, arrayLike2],
-    [rObjectLike2, arrayLike2],
-  ];
-
-  entries.forEach(([input, verifiedOutput]) => {
-    const converted = protojs.inverseCorrectArrayKeys(input);
-    expect(converted).toStrictEqual(verifiedOutput);
-  });
-});
-
-test('can convert array-like to object-like', () => {
-  // [ array-like input, object-like verified output ]
-  const entries = [
-    [arrayLike1, rObjectLike1],
-    [arrayLike2, rObjectLike2],
-  ];
-
-  entries.forEach(([input, verifiedOutput]) => {
-    const converted = protojs.correctArrayKeys(input);
-    expect(converted).toStrictEqual(verifiedOutput);
-  });
-});
-
-test('empty object can be converted to array-like form', () => {
-  const object = {
-    1: {},
-  };
-  const converted = protojs.inverseCorrectArrayKeys(object);
-  expect(converted).toStrictEqual([[]]);
-});
diff --git a/src/common/protojs.test.ts b/src/common/protojs.test.ts
new file mode 100644
index 0000000..bc12854
--- /dev/null
+++ b/src/common/protojs.test.ts
@@ -0,0 +1,155 @@
+/* eslint-disable no-sparse-arrays */
+import { expect, test } from '@jest/globals';
+import * as protojs from './protojs.js';
+
+const objectLike1 = {
+  '2': [1, 2, 3],
+};
+
+const arrayLike1 = [undefined, [1, 2, 3]];
+
+const rObjectLike1 = [, undefined, [, 1, 2, 3]];
+
+const objectLike2 = {
+  '1': {
+    '1': 12,
+    '2': [
+      {
+        '6': [false, false, false],
+        '7': {
+          '1': false,
+          '2': 'Hola',
+        },
+      },
+      {
+        '6': [true, true, false],
+        '7': {
+          '1': false,
+          '2': 'Test',
+        },
+      },
+      {
+        '6': [],
+        '7': {
+          '1': true,
+          '2': 'Bye',
+        },
+      },
+    ],
+    '3': 1663,
+  },
+};
+
+const arrayLike2 = [
+  [
+    12,
+    [
+      [
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        [false, false, false],
+        [false, 'Hola'],
+      ],
+      [
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        [true, true, false],
+        [false, 'Test'],
+      ],
+      [
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        [],
+        [true, 'Bye'],
+      ],
+    ],
+    1663,
+  ],
+];
+
+const rObjectLike2 = [
+  ,
+  [
+    ,
+    12,
+    [
+      ,
+      [
+        ,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        [, false, false, false],
+        [, false, 'Hola'],
+      ],
+      [
+        ,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        [, true, true, false],
+        [, false, 'Test'],
+      ],
+      [
+        ,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        [],
+        [, true, 'Bye'],
+      ],
+    ],
+    1663,
+  ],
+];
+
+test('can convert object-like to array-like', () => {
+  // [ object-like input, array-like verified output ]
+  const entries = [
+    [objectLike1, arrayLike1],
+    [rObjectLike1, arrayLike1],
+    [objectLike2, arrayLike2],
+    [rObjectLike2, arrayLike2],
+  ];
+
+  entries.forEach(([input, verifiedOutput]) => {
+    const converted = protojs.inverseCorrectArrayKeys(input);
+    expect(converted).toStrictEqual(verifiedOutput);
+  });
+});
+
+test('can convert array-like to object-like', () => {
+  // [ array-like input, object-like verified output ]
+  const entries = [
+    [arrayLike1, rObjectLike1],
+    [arrayLike2, rObjectLike2],
+  ];
+
+  entries.forEach(([input, verifiedOutput]) => {
+    const converted = protojs.correctArrayKeys(input);
+    expect(converted).toStrictEqual(verifiedOutput);
+  });
+});
+
+test('empty object can be converted to array-like form', () => {
+  const object = {
+    1: {},
+  };
+  const converted = protojs.inverseCorrectArrayKeys(object);
+  expect(converted).toStrictEqual([[]]);
+});