diff --git a/.travis.yml b/.travis.yml
index bb164d8..fd60d6d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,7 +18,7 @@ install:
   - nvm install $NODE_VERSION
   - node --version
   - npm --version
-  - npm install
+  - npm run ci-or-install
 os:
   - linux
   - osx
diff --git a/appveyor.yml b/appveyor.yml
index 24e22b3..ca4d4cb 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -15,7 +15,7 @@ install:
   - set PATH=%APPDATA%\npm;%PATH%
   - node --version
   - npm --version
-  - npm install
+  - npm run ci-or-install
 
 matrix:
   fast_finish: false
diff --git a/package-lock.json b/package-lock.json
index f2ebfb5..4a3d67b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1057,6 +1057,7 @@
       "requires": {
         "anymatch": "1.3.2",
         "async-each": "1.0.1",
+        "fsevents": "1.2.4",
         "glob-parent": "2.0.0",
         "inherits": "2.0.3",
         "is-binary-path": "1.0.1",
@@ -2034,6 +2035,535 @@
       "resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
       "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
     },
+    "fsevents": {
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-1.2.4.tgz",
+      "integrity": "sha512-z8H8/diyk76B7q5wg+Ud0+CqzcAF3mBBI/bA5ne5zrRUUIvNkJY//D3BqyH571KuAC4Nr7Rw7CjWX4r0y9DvNg==",
+      "dev": true,
+      "optional": true,
+      "requires": {
+        "nan": "2.11.1",
+        "node-pre-gyp": "0.10.0"
+      },
+      "dependencies": {
+        "abbrev": {
+          "version": "1.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "ansi-regex": {
+          "version": "2.1.1",
+          "bundled": true,
+          "dev": true
+        },
+        "aproba": {
+          "version": "1.2.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "are-we-there-yet": {
+          "version": "1.1.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "delegates": "1.0.0",
+            "readable-stream": "2.3.6"
+          }
+        },
+        "balanced-match": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true
+        },
+        "brace-expansion": {
+          "version": "1.1.11",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "balanced-match": "1.0.0",
+            "concat-map": "0.0.1"
+          }
+        },
+        "chownr": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "code-point-at": {
+          "version": "1.1.0",
+          "bundled": true,
+          "dev": true
+        },
+        "concat-map": {
+          "version": "0.0.1",
+          "bundled": true,
+          "dev": true
+        },
+        "console-control-strings": {
+          "version": "1.1.0",
+          "bundled": true,
+          "dev": true
+        },
+        "core-util-is": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "debug": {
+          "version": "2.6.9",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
+        "deep-extend": {
+          "version": "0.5.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "delegates": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "detect-libc": {
+          "version": "1.0.3",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "fs-minipass": {
+          "version": "1.2.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "minipass": "2.2.4"
+          }
+        },
+        "fs.realpath": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "gauge": {
+          "version": "2.7.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "aproba": "1.2.0",
+            "console-control-strings": "1.1.0",
+            "has-unicode": "2.0.1",
+            "object-assign": "4.1.1",
+            "signal-exit": "3.0.2",
+            "string-width": "1.0.2",
+            "strip-ansi": "3.0.1",
+            "wide-align": "1.1.2"
+          }
+        },
+        "glob": {
+          "version": "7.1.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "fs.realpath": "1.0.0",
+            "inflight": "1.0.6",
+            "inherits": "2.0.3",
+            "minimatch": "3.0.4",
+            "once": "1.4.0",
+            "path-is-absolute": "1.0.1"
+          }
+        },
+        "has-unicode": {
+          "version": "2.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "iconv-lite": {
+          "version": "0.4.21",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "safer-buffer": "2.1.2"
+          }
+        },
+        "ignore-walk": {
+          "version": "3.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "minimatch": "3.0.4"
+          }
+        },
+        "inflight": {
+          "version": "1.0.6",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "once": "1.4.0",
+            "wrappy": "1.0.2"
+          }
+        },
+        "inherits": {
+          "version": "2.0.3",
+          "bundled": true,
+          "dev": true
+        },
+        "ini": {
+          "version": "1.3.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "is-fullwidth-code-point": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "number-is-nan": "1.0.1"
+          }
+        },
+        "isarray": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "minimatch": {
+          "version": "3.0.4",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "brace-expansion": "1.1.11"
+          }
+        },
+        "minimist": {
+          "version": "0.0.8",
+          "bundled": true,
+          "dev": true
+        },
+        "minipass": {
+          "version": "2.2.4",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "safe-buffer": "5.1.1",
+            "yallist": "3.0.2"
+          }
+        },
+        "minizlib": {
+          "version": "1.1.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "minipass": "2.2.4"
+          }
+        },
+        "mkdirp": {
+          "version": "0.5.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "minimist": "0.0.8"
+          }
+        },
+        "ms": {
+          "version": "2.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "needle": {
+          "version": "2.2.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "debug": "2.6.9",
+            "iconv-lite": "0.4.21",
+            "sax": "1.2.4"
+          }
+        },
+        "node-pre-gyp": {
+          "version": "0.10.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "detect-libc": "1.0.3",
+            "mkdirp": "0.5.1",
+            "needle": "2.2.0",
+            "nopt": "4.0.1",
+            "npm-packlist": "1.1.10",
+            "npmlog": "4.1.2",
+            "rc": "1.2.7",
+            "rimraf": "2.6.2",
+            "semver": "5.5.0",
+            "tar": "4.4.1"
+          }
+        },
+        "nopt": {
+          "version": "4.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "abbrev": "1.1.1",
+            "osenv": "0.1.5"
+          }
+        },
+        "npm-bundled": {
+          "version": "1.0.3",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "npm-packlist": {
+          "version": "1.1.10",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "ignore-walk": "3.0.1",
+            "npm-bundled": "1.0.3"
+          }
+        },
+        "npmlog": {
+          "version": "4.1.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "are-we-there-yet": "1.1.4",
+            "console-control-strings": "1.1.0",
+            "gauge": "2.7.4",
+            "set-blocking": "2.0.0"
+          }
+        },
+        "number-is-nan": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true
+        },
+        "object-assign": {
+          "version": "4.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "once": {
+          "version": "1.4.0",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "wrappy": "1.0.2"
+          }
+        },
+        "os-homedir": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "os-tmpdir": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "osenv": {
+          "version": "0.1.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "os-homedir": "1.0.2",
+            "os-tmpdir": "1.0.2"
+          }
+        },
+        "path-is-absolute": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "process-nextick-args": {
+          "version": "2.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "rc": {
+          "version": "1.2.7",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "deep-extend": "0.5.1",
+            "ini": "1.3.5",
+            "minimist": "1.2.0",
+            "strip-json-comments": "2.0.1"
+          },
+          "dependencies": {
+            "minimist": {
+              "version": "1.2.0",
+              "bundled": true,
+              "dev": true,
+              "optional": true
+            }
+          }
+        },
+        "readable-stream": {
+          "version": "2.3.6",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "core-util-is": "1.0.2",
+            "inherits": "2.0.3",
+            "isarray": "1.0.0",
+            "process-nextick-args": "2.0.0",
+            "safe-buffer": "5.1.1",
+            "string_decoder": "1.1.1",
+            "util-deprecate": "1.0.2"
+          }
+        },
+        "rimraf": {
+          "version": "2.6.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "glob": "7.1.2"
+          }
+        },
+        "safe-buffer": {
+          "version": "5.1.1",
+          "bundled": true,
+          "dev": true
+        },
+        "safer-buffer": {
+          "version": "2.1.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "sax": {
+          "version": "1.2.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "semver": {
+          "version": "5.5.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "set-blocking": {
+          "version": "2.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "signal-exit": {
+          "version": "3.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "string-width": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "code-point-at": "1.1.0",
+            "is-fullwidth-code-point": "1.0.0",
+            "strip-ansi": "3.0.1"
+          }
+        },
+        "string_decoder": {
+          "version": "1.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "safe-buffer": "5.1.1"
+          }
+        },
+        "strip-ansi": {
+          "version": "3.0.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "ansi-regex": "2.1.1"
+          }
+        },
+        "strip-json-comments": {
+          "version": "2.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "tar": {
+          "version": "4.4.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "chownr": "1.0.1",
+            "fs-minipass": "1.2.5",
+            "minipass": "2.2.4",
+            "minizlib": "1.1.0",
+            "mkdirp": "0.5.1",
+            "safe-buffer": "5.1.1",
+            "yallist": "3.0.2"
+          }
+        },
+        "util-deprecate": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "wide-align": {
+          "version": "1.1.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "string-width": "1.0.2"
+          }
+        },
+        "wrappy": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true
+        },
+        "yallist": {
+          "version": "3.0.2",
+          "bundled": true,
+          "dev": true
+        }
+      }
+    },
     "function-bind": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.1.tgz",
@@ -3274,6 +3804,13 @@
       "integrity": "sha1-j7+rsKmKJT0xhDMfno3rc3L6xsA=",
       "dev": true
     },
+    "nan": {
+      "version": "2.11.1",
+      "resolved": "https://registry.npmjs.org/nan/-/nan-2.11.1.tgz",
+      "integrity": "sha512-iji6k87OSXa0CcrLl9z+ZiYSuR2o+c0bGuNmXdrhTQTakxytAFsC56SArGYoiHlJlFoHSnvmhpceZJaXkVuOtA==",
+      "dev": true,
+      "optional": true
+    },
     "next-tick": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/next-tick/-/next-tick-1.0.0.tgz",
diff --git a/package.json b/package.json
index fd9e02d..c4e8a55 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,7 @@
     "src"
   ],
   "scripts": {
+    "ci-or-install": "node scripts/ci-or-install",
     "posttest": "npm run lint",
     "test": "nyc --reporter=text --reporter=lcov ava test/*.js",
     "test-no-coverage": "ava test/*.js",
diff --git a/scripts/ci-or-install.js b/scripts/ci-or-install.js
new file mode 100755
index 0000000..e71cd1e
--- /dev/null
+++ b/scripts/ci-or-install.js
@@ -0,0 +1,41 @@
+#!/usr/bin/env node
+var childProcess = require('child_process');
+// Note: can't use 3P modules or shelljs, because this must run before we
+// download dependencies.
+
+// Also, we must use exec{Sync} because `npm` is a batch script on Windows,
+// which must run in-process in the shell, and the 'shell' option isn't
+// supported on node v4.
+
+function Version(components) {
+  this.components = components;
+}
+
+Version.prototype.isAtLeast = function (other) {
+  if (this.components.length !== 3 || other.components.length !== 3) {
+    throw new Error('version numbers must have 3 components.');
+  }
+  for (var k = 0; k < this.components.length; k++) {
+    if (this.components[k] > other.components[k]) return true;
+    if (this.components[k] < other.components[k]) return false;
+  }
+  // At this point, the components must be equal.
+  return true;
+};
+
+var npmVersionComponents = childProcess.execSync('npm --version')
+    .toString().trim().split('.').map(function (str) {
+      return parseInt(str, 10);
+    });
+var npmVersion = new Version(npmVersionComponents);
+var minimumVersionWithNpmCi = new Version([5, 7, 0]);
+
+var subcommand = npmVersion.isAtLeast(minimumVersionWithNpmCi) ?
+  'ci' :
+  'install';
+
+console.log('Executing `npm ' + subcommand + '`');
+// Async. Node waits until this is finished.
+var c = childProcess.exec('npm ' + subcommand);
+c.stdout.pipe(process.stdout);
+c.stderr.pipe(process.stderr);