diff --git a/package.json b/package.json
index e64586c..d9b9470 100644
--- a/package.json
+++ b/package.json
@@ -58,7 +58,7 @@
     "tslint": "^5.9.1",
     "typedoc": "^0.11.0",
     "typescript": "^2.7.2",
-    "webpack": "^3.10.0"
+    "webpack": "^4.5.0"
   },
   "author": {
     "name": "narazaka",