diff --git a/.travis.yml b/.travis.yml
index fe0161d..d4faff9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,8 +5,21 @@ os:
   - osx
 node_js:
   - node
-  - "6"
   - "5"
   - "4"
-
-script: npm test
+env:
+  - export WEBPACK_VERSION="2.1.0-beta"
+  - export WEBPACK_VERSION="1.13.0"
+matrix:
+  fast_finish: true
+before_install:
+  - nvm --version
+  - node --version
+  - npm --version
+before_script:
+  - 'if [ "$WEBPACK_VERSION" ]; then npm install webpack@^$WEBPACK_VERSION; fi'
+script:
+  - npm run build
+  - npm test
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/gulpfile.js b/gulpfile.js
index 5bde739..7e0d9e4 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -1,3 +1,5 @@
+'use strict' // eslint-disable-line strict
+
 const gulp = require('gulp')
 const del = require('del')
 const util = require('gulp-util')
diff --git a/package.json b/package.json
index 9135337..03bc3a7 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
     "url": "https://github.com/webpack/karma-webpack.git"
   },
   "peerDependencies": {
-    "webpack": "^1.4.0 || ^2 || ^2.1.0-beta"
+    "webpack": "^1.1.0 || ^2 || ^2.1.0-beta"
   },
   "dependencies": {
     "async": "~0.9.0",
@@ -66,8 +66,7 @@
     "karma-chrome-launcher": "~1.0.1",
     "karma-mocha": "~1.1.1",
     "karma-spec-reporter": "~0.0.22",
-    "mocha": "^2.5.3",
-    "webpack": "^2.1.0-beta.20"
+    "mocha": "^2.5.3"
   },
   "config": {
     "commitizen": {