diff --git a/integration_tests/__tests__/only_changed.test.js b/integration_tests/__tests__/only_changed.test.js
index d280c51de0c5..6e3bb9900a74 100644
--- a/integration_tests/__tests__/only_changed.test.js
+++ b/integration_tests/__tests__/only_changed.test.js
@@ -73,3 +73,60 @@ test('run only changed files', () => {
   expect(stderr).toMatch('PASS  __tests__/file2.test.js');
   expect(stderr).toMatch('PASS  __tests__/file3.test.js');
 });
+
+test('onlyChanged in config is overwritten by --all', () => {
+  writeFiles(DIR, {
+    '.watchmanconfig': '',
+    '__tests__/file1.test.js': `require('../file1'); test('file1', () => {});`,
+    'file1.js': 'module.exports = {}',
+    'package.json': JSON.stringify({jest: {onlyChanged: true}}),
+  });
+  let stderr;
+  let stdout;
+
+  ({stdout} = runJest(DIR));
+  expect(stdout).toMatch(/Jest can only find uncommitted changed files/);
+
+  run(`${GIT} init`, DIR);
+  run(`${GIT} add .`, DIR);
+  run(`${GIT} commit -m "first"`, DIR);
+
+  ({stdout} = runJest(DIR));
+  expect(stdout).toMatch('No tests found related to files');
+
+  ({stderr} = runJest(DIR, ['--lastCommit']));
+  expect(stderr).toMatch('PASS  __tests__/file1.test.js');
+
+  writeFiles(DIR, {
+    '__tests__/file2.test.js': `require('../file2'); test('file2', () => {});`,
+    '__tests__/file3.test.js': `require('../file3'); test('file3', () => {});`,
+    'file2.js': 'module.exports = {}',
+    'file3.js': `require('./file2')`,
+  });
+
+  ({stderr} = runJest(DIR));
+
+  expect(stderr).not.toMatch('PASS  __tests__/file1.test.js');
+  expect(stderr).toMatch('PASS  __tests__/file2.test.js');
+  expect(stderr).toMatch('PASS  __tests__/file3.test.js');
+
+  run(`${GIT} add .`, DIR);
+  run(`${GIT} commit -m "second"`, DIR);
+
+  ({stderr} = runJest(DIR));
+  expect(stdout).toMatch('No tests found related to files');
+
+  writeFiles(DIR, {
+    'file2.js': 'module.exports = {modified: true}',
+  });
+
+  ({stderr} = runJest(DIR));
+  expect(stderr).not.toMatch('PASS  __tests__/file1.test.js');
+  expect(stderr).toMatch('PASS  __tests__/file2.test.js');
+  expect(stderr).toMatch('PASS  __tests__/file3.test.js');
+
+  ({stderr} = runJest(DIR, ['--all']));
+  expect(stderr).toMatch('PASS  __tests__/file1.test.js');
+  expect(stderr).toMatch('PASS  __tests__/file2.test.js');
+  expect(stderr).toMatch('PASS  __tests__/file3.test.js');
+});
diff --git a/packages/jest-cli/src/cli/args.js b/packages/jest-cli/src/cli/args.js
index 3ff7fee81696..9c1c03312ade 100644
--- a/packages/jest-cli/src/cli/args.js
+++ b/packages/jest-cli/src/cli/args.js
@@ -51,6 +51,13 @@ const usage = 'Usage: $0 [--config=<pathToConfigFile>] [TestPathPattern]';
 const docs = 'Documentation: https://facebook.github.io/jest/';
 
 const options = {
+  all: {
+    default: undefined,
+    description:
+      'The opposite of `onlyChanged`. If `onlyChanged` is set by ' +
+      'default, running jest with `--all` will force Jest to run all tests ' +
+      'instead of runnig only tests related to changed files.',
+  },
   automock: {
     default: undefined,
     description: 'Automock all files by default.',
diff --git a/packages/jest-config/src/normalize.js b/packages/jest-config/src/normalize.js
index a10c4dbc1d94..8f0084fd1090 100644
--- a/packages/jest-config/src/normalize.js
+++ b/packages/jest-config/src/normalize.js
@@ -492,6 +492,10 @@ function normalize(options: InitialOptions, argv: Argv) {
   newOptions.json = argv.json;
   newOptions.lastCommit = argv.lastCommit;
 
+  if (argv.all) {
+    newOptions.onlyChanged = false;
+  }
+
   newOptions.updateSnapshot =
     argv.ci && !argv.updateSnapshot
       ? 'none'
diff --git a/types/Argv.js b/types/Argv.js
index d98a99f3e80f..25ae5c7a83b9 100644
--- a/types/Argv.js
+++ b/types/Argv.js
@@ -12,6 +12,7 @@
 export type Argv = {|
   _: Array<string>,
   $0: string,
+  all: boolean,
   automock: boolean,
   bail: boolean,
   browser: boolean,