diff --git a/.travis.yml b/.travis.yml
index 5f9dabd7d7..cc13890478 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,11 @@ before_install:
 - git remote set-branches origin master && git fetch
 - git checkout master
 - git checkout -
-- npm install -g npm
+# On 0.12, we want to test with the default version of npm, otherwise
+# upgrade to the latest.
+- if [[ ${TRAVIS_NODE_VERSION:0:1} -gt "0" ]]; then
+    npm install -g npm;
+  fi
 script:
 - COVERAGE=y npm test
 # Run changelog-lint but only on newer versions of Node (because of syntax errors)
diff --git a/README.md b/README.md
index c447a7e544..60ae6f0ced 100644
--- a/README.md
+++ b/README.md
@@ -19,24 +19,13 @@ cross-platform way. Initially, it will provide a streamlined experience for deve
 
 ## Installation from npm
 
-First, make sure your `npm` is up to date.
-You will need npm greater than version `3.0.0`:
-
-    npm install --global npm
-
-If you're on Windows, you will also need to
-[follow these instructions](https://github.com/npm/npm/wiki/Troubleshooting#upgrading-on-windows)
-after upgrading npm.
-
-Install `web-ext`:
-
     npm install --global web-ext
 
 ## Installation from source
 
 You'll need:
 * [Node.js](https://nodejs.org/en/), 0.12 or higher
-* [npm](https://www.npmjs.com/), 3.0.0 or higher
+* [npm](https://www.npmjs.com/), 3.0.0 or higher is recommended
 
 Optionally, you may like:
 * [nvm](https://github.com/creationix/nvm), which helps manage node versions
@@ -46,10 +35,6 @@ you may need to uninstall it first:
 
     npm uninstall --global web-ext
 
-Make sure `npm` is up to date:
-
-    npm install --global npm
-
 Change into the source and install all dependencies:
 
     git clone https://github.com/mozilla/web-ext.git
diff --git a/package.json b/package.json
index d650c0b96a..28a5e49208 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,7 @@
     "minimatch": "3.0.2",
     "mz": "2.4.0",
     "node-firefox-connect": "1.2.0",
-    "sign-addon": "0.1.1",
+    "sign-addon": "0.1.2",
     "source-map-support": "0.4.2",
     "stream-to-promise": "2.1.1",
     "tmp": "0.0.28",
diff --git a/src/cmd/sign.js b/src/cmd/sign.js
index 1e6ed2aee8..be845a1060 100644
--- a/src/cmd/sign.js
+++ b/src/cmd/sign.js
@@ -1,6 +1,6 @@
 /* @flow */
 import path from 'path';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {signAddon as defaultAddonSigner} from '../util/es6-modules';
 
 import defaultBuilder from './build';
diff --git a/src/firefox/index.js b/src/firefox/index.js
index 74487b6de7..18c6a845a0 100644
--- a/src/firefox/index.js
+++ b/src/firefox/index.js
@@ -5,7 +5,7 @@ import defaultFxRunner from 'fx-runner/lib/run';
 import FirefoxProfile, {copyFromUserProfile as defaultUserProfileCopier}
   from 'firefox-profile';
 import streamToPromise from 'stream-to-promise';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 
 import isDirectory from '../util/is-directory';
 import {promisify} from '../util/es6-modules';
diff --git a/src/util/artifacts.js b/src/util/artifacts.js
index ca06f01d12..f1e2bae53f 100644
--- a/src/util/artifacts.js
+++ b/src/util/artifacts.js
@@ -1,5 +1,5 @@
 /* @flow */
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {WebExtError, onlyErrorsWithCode} from '../errors';
 import {createLogger} from './logger';
 
diff --git a/src/util/is-directory.js b/src/util/is-directory.js
index c91809a544..37e07427df 100644
--- a/src/util/is-directory.js
+++ b/src/util/is-directory.js
@@ -1,5 +1,5 @@
 /* @flow */
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {onlyErrorsWithCode} from '../errors';
 
 
diff --git a/src/util/manifest.js b/src/util/manifest.js
index 9f0fba5bce..6183cbfd5f 100644
--- a/src/util/manifest.js
+++ b/src/util/manifest.js
@@ -1,7 +1,7 @@
 /* @flow */
 import path from 'path';
 
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {InvalidManifest} from '../errors';
 import {createLogger} from './logger';
 
diff --git a/tests/test-cmd/test.build.js b/tests/test-cmd/test.build.js
index 43edd08883..96962c0db6 100644
--- a/tests/test-cmd/test.build.js
+++ b/tests/test-cmd/test.build.js
@@ -1,5 +1,5 @@
 /* @flow */
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import path from 'path';
 import {it, describe} from 'mocha';
 import {assert} from 'chai';
diff --git a/tests/test-cmd/test.sign.js b/tests/test-cmd/test.sign.js
index 9c0f029c94..02d036157e 100644
--- a/tests/test-cmd/test.sign.js
+++ b/tests/test-cmd/test.sign.js
@@ -1,7 +1,7 @@
 /* @flow */
 import path from 'path';
 import copyDir from 'copy-dir';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {describe, it} from 'mocha';
 import {assert} from 'chai';
 import sinon from 'sinon';
diff --git a/tests/test-firefox/test.firefox.js b/tests/test-firefox/test.firefox.js
index 3917e27594..383e1e3030 100644
--- a/tests/test-firefox/test.firefox.js
+++ b/tests/test-firefox/test.firefox.js
@@ -8,7 +8,7 @@ import FirefoxProfile from 'firefox-profile';
 
 import * as firefox from '../../src/firefox';
 import {onlyInstancesOf, WebExtError} from '../../src/errors';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {withTempDir} from '../../src/util/temp-dir';
 import {TCPConnectError, fixturePath, fake, makeSureItFails} from '../helpers';
 import {basicManifest, manifestWithoutApps} from '../test-util/test.manifest';
diff --git a/tests/test-util/test.artifacts.js b/tests/test-util/test.artifacts.js
index 29132a0638..99ddca158c 100644
--- a/tests/test-util/test.artifacts.js
+++ b/tests/test-util/test.artifacts.js
@@ -2,7 +2,7 @@
 import path from 'path';
 import {it, describe} from 'mocha';
 import {assert} from 'chai';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 
 import {onlyInstancesOf, WebExtError} from '../../src/errors';
 import {withTempDir} from '../../src/util/temp-dir';
diff --git a/tests/test-util/test.is-directory.js b/tests/test-util/test.is-directory.js
index 3cc3e83e9b..fd7562e896 100644
--- a/tests/test-util/test.is-directory.js
+++ b/tests/test-util/test.is-directory.js
@@ -1,6 +1,6 @@
 /* @flow */
 import path from 'path';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {assert} from 'chai';
 import {describe, it} from 'mocha';
 
diff --git a/tests/test-util/test.manifest.js b/tests/test-util/test.manifest.js
index 3962533905..74c19c6baf 100644
--- a/tests/test-util/test.manifest.js
+++ b/tests/test-util/test.manifest.js
@@ -5,7 +5,7 @@ import {assert} from 'chai';
 import deepcopy from 'deepcopy';
 
 import {onlyInstancesOf, InvalidManifest} from '../../src/errors';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import getValidatedManifest, {getManifestId} from '../../src/util/manifest';
 import {withTempDir} from '../../src/util/temp-dir';
 import {makeSureItFails} from '../helpers';
diff --git a/tests/test-util/test.temp-dir.js b/tests/test-util/test.temp-dir.js
index 1ce05a3480..ff0b233cb9 100644
--- a/tests/test-util/test.temp-dir.js
+++ b/tests/test-util/test.temp-dir.js
@@ -1,6 +1,6 @@
 /* @flow */
 import {describe, it} from 'mocha';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import {assert} from 'chai';
 
 import {withTempDir, TempDir} from '../../src/util/temp-dir';
diff --git a/tests/test.program.js b/tests/test.program.js
index 4f177ab320..d7b1ced0f8 100644
--- a/tests/test.program.js
+++ b/tests/test.program.js
@@ -1,7 +1,7 @@
 /* @flow */
 import {describe, it} from 'mocha';
 import path from 'path';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import sinon from 'sinon';
 import {assert} from 'chai';
 import {spy} from 'sinon';
diff --git a/tests/test.watcher.js b/tests/test.watcher.js
index 7e51f2be0d..3fae0c9930 100644
--- a/tests/test.watcher.js
+++ b/tests/test.watcher.js
@@ -1,7 +1,7 @@
 /* @flow */
 import path from 'path';
 import {it, describe} from 'mocha';
-import fs from 'mz/fs';
+import {fs} from 'mz';
 import sinon from 'sinon';
 import {assert} from 'chai';