diff --git a/packages/jest-haste-map/src/crawlers/__tests__/node.test.js b/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
index d9b8229a285b..1d10eea8cf20 100644
--- a/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
+++ b/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
@@ -34,8 +34,6 @@ jest.mock('child_process', () => ({
   }),
 }));
 
-let mockHasReaddirWithFileTypesSupport = false;
-
 jest.mock('graceful-fs', () => {
   const slash = require('slash');
   let mtime = 32;
@@ -73,55 +71,42 @@ jest.mock('graceful-fs', () => {
         throw new Error('readdir: callback is not a function!');
       }
 
-      if (mockHasReaddirWithFileTypesSupport) {
-        if (slash(dir) === '/project/fruits') {
-          setTimeout(
-            () =>
-              callback(null, [
-                {
-                  isDirectory: () => true,
-                  isSymbolicLink: () => false,
-                  name: 'directory',
-                },
-                {
-                  isDirectory: () => false,
-                  isSymbolicLink: () => false,
-                  name: 'tomato.js',
-                },
-                {
-                  isDirectory: () => false,
-                  isSymbolicLink: () => true,
-                  name: 'symlink',
-                },
-              ]),
-            0,
-          );
-        } else if (slash(dir) === '/project/fruits/directory') {
-          setTimeout(
-            () =>
-              callback(null, [
-                {
-                  isDirectory: () => false,
-                  isSymbolicLink: () => false,
-                  name: 'strawberry.js',
-                },
-              ]),
-            0,
-          );
-        } else if (slash(dir) == '/error') {
-          setTimeout(() => callback({code: 'ENOTDIR'}, undefined), 0);
-        }
-      } else {
-        if (slash(dir) === '/project/fruits') {
-          setTimeout(
-            () => callback(null, ['directory', 'tomato.js', 'symlink']),
-            0,
-          );
-        } else if (slash(dir) === '/project/fruits/directory') {
-          setTimeout(() => callback(null, ['strawberry.js']), 0);
-        } else if (slash(dir) == '/error') {
-          setTimeout(() => callback({code: 'ENOTDIR'}, undefined), 0);
-        }
+      if (slash(dir) === '/project/fruits') {
+        setTimeout(
+          () =>
+            callback(null, [
+              {
+                isDirectory: () => true,
+                isSymbolicLink: () => false,
+                name: 'directory',
+              },
+              {
+                isDirectory: () => false,
+                isSymbolicLink: () => false,
+                name: 'tomato.js',
+              },
+              {
+                isDirectory: () => false,
+                isSymbolicLink: () => true,
+                name: 'symlink',
+              },
+            ]),
+          0,
+        );
+      } else if (slash(dir) === '/project/fruits/directory') {
+        setTimeout(
+          () =>
+            callback(null, [
+              {
+                isDirectory: () => false,
+                isSymbolicLink: () => false,
+                name: 'strawberry.js',
+              },
+            ]),
+          0,
+        );
+      } else if (slash(dir) == '/error') {
+        setTimeout(() => callback({code: 'ENOTDIR'}, undefined), 0);
       }
     }),
     stat: jest.fn(stat),
@@ -379,65 +364,30 @@ describe('node crawler', () => {
     expect(removedFiles).toEqual(new Map());
   });
 
-  describe('readdir withFileTypes support', () => {
-    it('calls lstat for directories and symlinks if readdir withFileTypes is not supported', async () => {
-      nodeCrawl = require('../node');
-      const fs = require('graceful-fs');
-
-      const files = new Map();
-      const {hasteMap, removedFiles} = await nodeCrawl({
-        data: {files},
-        extensions: ['js'],
-        forceNodeFilesystemAPI: true,
-        ignore: pearMatcher,
-        rootDir,
-        roots: ['/project/fruits'],
-      });
-
-      expect(hasteMap.files).toEqual(
-        createMap({
-          'fruits/directory/strawberry.js': ['', 33, 42, 0, '', null],
-          'fruits/tomato.js': ['', 32, 42, 0, '', null],
-        }),
-      );
-      expect(removedFiles).toEqual(new Map());
-      // once for /project/fruits, once for /project/fruits/directory
-      expect(fs.readdir).toHaveBeenCalledTimes(2);
-      // once for each of:
-      // 1. /project/fruits/directory
-      // 2. /project/fruits/directory/strawberry.js
-      // 3. /project/fruits/tomato.js
-      // 4. /project/fruits/symlink
-      // (we never call lstat on the root /project/fruits, since we know it's a directory)
-      expect(fs.lstat).toHaveBeenCalledTimes(4);
-    });
+  it('avoids calling lstat for directories and symlinks', async () => {
+    nodeCrawl = require('../node');
+    const fs = require('graceful-fs');
 
-    it('avoids calling lstat for directories and symlinks if readdir withFileTypes is supported', async () => {
-      mockHasReaddirWithFileTypesSupport = true;
-      nodeCrawl = require('../node');
-      const fs = require('graceful-fs');
-
-      const files = new Map();
-      const {hasteMap, removedFiles} = await nodeCrawl({
-        data: {files},
-        extensions: ['js'],
-        forceNodeFilesystemAPI: true,
-        ignore: pearMatcher,
-        rootDir,
-        roots: ['/project/fruits'],
-      });
-
-      expect(hasteMap.files).toEqual(
-        createMap({
-          'fruits/directory/strawberry.js': ['', 33, 42, 0, '', null],
-          'fruits/tomato.js': ['', 32, 42, 0, '', null],
-        }),
-      );
-      expect(removedFiles).toEqual(new Map());
-      // once for /project/fruits, once for /project/fruits/directory
-      expect(fs.readdir).toHaveBeenCalledTimes(2);
-      // once for strawberry.js, once for tomato.js
-      expect(fs.lstat).toHaveBeenCalledTimes(2);
+    const files = new Map();
+    const {hasteMap, removedFiles} = await nodeCrawl({
+      data: {files},
+      extensions: ['js'],
+      forceNodeFilesystemAPI: true,
+      ignore: pearMatcher,
+      rootDir,
+      roots: ['/project/fruits'],
     });
+
+    expect(hasteMap.files).toEqual(
+      createMap({
+        'fruits/directory/strawberry.js': ['', 33, 42, 0, '', null],
+        'fruits/tomato.js': ['', 32, 42, 0, '', null],
+      }),
+    );
+    expect(removedFiles).toEqual(new Map());
+    // once for /project/fruits, once for /project/fruits/directory
+    expect(fs.readdir).toHaveBeenCalledTimes(2);
+    // once for strawberry.js, once for tomato.js
+    expect(fs.lstat).toHaveBeenCalledTimes(2);
   });
 });
diff --git a/packages/jest-haste-map/src/crawlers/node.ts b/packages/jest-haste-map/src/crawlers/node.ts
index 58fc9ccf442d..88d15678706d 100644
--- a/packages/jest-haste-map/src/crawlers/node.ts
+++ b/packages/jest-haste-map/src/crawlers/node.ts
@@ -74,27 +74,19 @@ function find(
         callback(result);
         return;
       }
-      // node < v10.10 does not support the withFileTypes option, and
-      // entry will be a string.
-      entries.forEach((entry: string | fs.Dirent) => {
-        const file = path.join(
-          directory,
-          typeof entry === 'string' ? entry : entry.name,
-        );
+      entries.forEach(entry => {
+        const file = path.join(directory, entry.name);
 
         if (ignore(file)) {
           return;
         }
 
-        if (typeof entry !== 'string') {
-          if (entry.isSymbolicLink()) {
-            return;
-          }
-
-          if (entry.isDirectory()) {
-            search(file);
-            return;
-          }
+        if (entry.isSymbolicLink()) {
+          return;
+        }
+        if (entry.isDirectory()) {
+          search(file);
+          return;
         }
 
         activeCalls++;
diff --git a/packages/jest-resolve/src/isBuiltinModule.ts b/packages/jest-resolve/src/isBuiltinModule.ts
index df64cc3d422f..a80fa949e540 100644
--- a/packages/jest-resolve/src/isBuiltinModule.ts
+++ b/packages/jest-resolve/src/isBuiltinModule.ts
@@ -7,12 +7,7 @@
 
 import module = require('module');
 
-// TODO: remove when we drop support for node v10 - it is included from node v12
-const EXPERIMENTAL_MODULES = ['worker_threads'];
-
-const BUILTIN_MODULES = new Set(
-  module.builtinModules.concat(EXPERIMENTAL_MODULES),
-);
+const BUILTIN_MODULES = new Set(module.builtinModules);
 
 export default function isBuiltinModule(module: string): boolean {
   return BUILTIN_MODULES.has(module);
diff --git a/packages/jest-worker/src/__tests__/process-integration.test.js b/packages/jest-worker/src/__tests__/process-integration.test.js
index 50fffc721e17..d5e3f0950504 100644
--- a/packages/jest-worker/src/__tests__/process-integration.test.js
+++ b/packages/jest-worker/src/__tests__/process-integration.test.js
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-'use strict';
-
 import EventEmitter from 'events';
 import {CHILD_MESSAGE_CALL, PARENT_MESSAGE_OK} from '../types';
 
@@ -37,10 +35,6 @@ function assertCallsToChild(childNum, ...calls) {
   });
 }
 
-jest.mock('worker_threads', () => {
-  throw Error('Unsupported');
-});
-
 describe('Jest Worker Integration', () => {
   beforeEach(() => {
     mockForkedProcesses = [];
diff --git a/packages/jest-worker/src/workers/messageParent.ts b/packages/jest-worker/src/workers/messageParent.ts
index d4a389055fc0..8c9127395aa6 100644
--- a/packages/jest-worker/src/workers/messageParent.ts
+++ b/packages/jest-worker/src/workers/messageParent.ts
@@ -5,29 +5,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {isMainThread, parentPort} from 'worker_threads';
 import {PARENT_MESSAGE_CUSTOM} from '../types';
 
-const isWorkerThread: boolean = (() => {
-  try {
-    // `Require` here to support Node v10
-    const {isMainThread, parentPort} =
-      require('worker_threads') as typeof import('worker_threads');
-    return !isMainThread && parentPort != null;
-  } catch {
-    return false;
-  }
-})();
-
 export default function messageParent(
   message: unknown,
   parentProcess = process,
 ): void {
-  if (isWorkerThread) {
-    // `Require` here to support Node v10
-    const {parentPort} =
-      require('worker_threads') as typeof import('worker_threads');
-    // ! is safe due to `null` check in `isWorkerThread`
-    parentPort!.postMessage([PARENT_MESSAGE_CUSTOM, message]);
+  if (!isMainThread && parentPort != null) {
+    parentPort.postMessage([PARENT_MESSAGE_CUSTOM, message]);
   } else if (typeof parentProcess.send === 'function') {
     parentProcess.send([PARENT_MESSAGE_CUSTOM, message]);
   } else {