diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c60e81dd02b..4f32bc6a534b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -118,6 +118,7 @@
 - `[jest-config]` Normalize `config.cwd` and `config.rootDir` using `realpath ([#7598](https://github.com/facebook/jest/pull/7598))
 - `[jest-environment-node]` Fix buffer property is not ArrayBuffer issue. ([#7626](https://github.com/facebook/jest/pull/7626))
 - `[babel-plugin-jest-hoist]` Ignore TS type annotations when looking for out-of-scope references ([#7641](https://github.com/facebook/jest/pull/7641))
+- `[jest-config]` Add name to project if one does not exist to pick correct resolver ([#5862](https://github.com/facebook/jest/pull/5862))
 
 ### Chore & Maintenance
 
diff --git a/e2e/__tests__/multiProjectRunner.test.js b/e2e/__tests__/multiProjectRunner.test.js
index b423df611b51..b3438cb90905 100644
--- a/e2e/__tests__/multiProjectRunner.test.js
+++ b/e2e/__tests__/multiProjectRunner.test.js
@@ -399,3 +399,41 @@ test('Does transform files with the corresponding project transformer', () => {
   expect(stderr).toMatch('PASS project1/__tests__/project1.test.js');
   expect(stderr).toMatch('PASS project2/__tests__/project2.test.js');
 });
+
+test("doesn't bleed module file extensions resolution with multiple workers", () => {
+  writeFiles(DIR, {
+    '.watchmanconfig': '',
+    'file.js': 'module.exports = "file1"',
+    'file.p2.js': 'module.exports = "file2"',
+    'package.json': '{}',
+    'project1/__tests__/project1.test.js': `
+      const file = require('../../file');
+      test('file 1', () => expect(file).toBe('file1'));
+    `,
+    'project1/jest.config.js': `
+      module.exports = {
+        rootDir: '..',
+      };`,
+    'project2/__tests__/project2.test.js': `
+      const file = require('../../file');
+      test('file 2', () => expect(file).toBe('file2'));
+    `,
+    'project2/jest.config.js': `
+      module.exports = {
+        rootDir: '..',
+        moduleFileExtensions: ['p2.js', 'js']
+      };`,
+  });
+
+  const {stderr} = runJest(DIR, [
+    '--no-watchman',
+    '-w=2',
+    '--projects',
+    'project1',
+    'project2',
+  ]);
+
+  expect(stderr).toMatch('Ran all test suites in 2 projects.');
+  expect(stderr).toMatch('PASS project1/__tests__/project1.test.js');
+  expect(stderr).toMatch('PASS project2/__tests__/project2.test.js');
+});
diff --git a/packages/jest-config/package.json b/packages/jest-config/package.json
index f41992144802..63d03d525a13 100644
--- a/packages/jest-config/package.json
+++ b/packages/jest-config/package.json
@@ -23,7 +23,8 @@
     "jest-validate": "^23.6.0",
     "micromatch": "^3.1.10",
     "pretty-format": "^23.6.0",
-    "realpath-native": "^1.0.2"
+    "realpath-native": "^1.0.2",
+    "uuid": "^3.3.2"
   },
   "engines": {
     "node": ">= 6"
diff --git a/packages/jest-config/src/__tests__/normalize.test.js b/packages/jest-config/src/__tests__/normalize.test.js
index 6e021f4e81e4..ffebc661caa9 100644
--- a/packages/jest-config/src/__tests__/normalize.test.js
+++ b/packages/jest-config/src/__tests__/normalize.test.js
@@ -12,7 +12,6 @@ import normalize from '../normalize';
 jest.mock('jest-resolve');
 jest.mock('path', () => jest.requireActual('path').posix);
 
-const crypto = require('crypto');
 const path = require('path');
 const DEFAULT_JS_PATTERN = require('../constants').DEFAULT_JS_PATTERN;
 const DEFAULT_CSS_PATTERN = '^.+\\.(css)$';
@@ -47,20 +46,16 @@ beforeEach(() => {
   require('jest-resolve').findNodeModule = findNodeModule;
 });
 
-it('picks a name based on the rootDir', () => {
+it('assigns a random 32-byte hash as a name to avoid clashes', () => {
   const rootDir = '/root/path/foo';
-  const expected = crypto
-    .createHash('md5')
-    .update('/root/path/foo')
-    .digest('hex');
-  expect(
-    normalize(
-      {
-        rootDir,
-      },
-      {},
-    ).options.name,
-  ).toBe(expected);
+  const {name: name1} = normalize({rootDir}, {}).options;
+  const {name: name2} = normalize({rootDir}, {}).options;
+
+  expect(name1).toEqual(expect.any(String));
+  expect(name1).toHaveLength(32);
+  expect(name2).toEqual(expect.any(String));
+  expect(name2).toHaveLength(32);
+  expect(name1).not.toBe(name2);
 });
 
 it('keeps custom names based on the rootDir', () => {
diff --git a/packages/jest-config/src/normalize.js b/packages/jest-config/src/normalize.js
index a001625daf47..f63714494aca 100644
--- a/packages/jest-config/src/normalize.js
+++ b/packages/jest-config/src/normalize.js
@@ -17,6 +17,7 @@ import type {
 } from 'types/Config';
 
 import crypto from 'crypto';
+import uuid from 'uuid/v4';
 import glob from 'glob';
 import path from 'path';
 import {ValidationError, validate} from 'jest-validate';
@@ -268,6 +269,7 @@ const normalizeMissingOptions = (options: InitialOptions): InitialOptions => {
     options.name = crypto
       .createHash('md5')
       .update(options.rootDir)
+      .update(uuid())
       .digest('hex');
   }