diff --git a/package.json b/package.json
index 1c4eb56..bde6242 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "url": "https://github.com/webpack/karma-webpack.git"
   },
   "peerDependencies": {
-    "webpack": "^1.0.0 || ^2.0.0 || ^3.0.0"
+    "webpack": "^1.0.0 || ^2.0.0 || ^3.0.0 || ^4.0.0"
   },
   "dependencies": {
     "async": "~0.9.0",