diff --git a/package.json b/package.json
index 52dd3af..c5ad88a 100644
--- a/package.json
+++ b/package.json
@@ -41,12 +41,12 @@
     "cross-env": "^3.1.4",
     "css-loader": "^0.26.1",
     "dirty-chai": "^1.2.2",
-    "dotenv": "^2.0.0",
+    "dotenv": "^4.0.0",
     "elm": "^0.18.0",
     "elm-hot-loader": "^0.5.4",
     "elm-test": "^0.18.2",
     "elm-webpack-loader": "^4.1.1",
-    "eslint": "^3.12.2",
+    "eslint": "^3.13.0",
     "eslint-loader": "^1.6.1",
     "extract-text-webpack-plugin": "^1.0.1",
     "file-loader": "^0.9.0",
@@ -62,7 +62,7 @@
     "karma-phantomjs-launcher": "^1.0.2",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^1.8.1",
-    "less": "^2.7.1",
+    "less": "^2.7.2",
     "less-loader": "^2.2.3",
     "mocha": "^3.2.0",
     "node-elm-compiler": "^4.2.1",
diff --git a/webpack.config.babel.js b/webpack.config.babel.js
index f28be87..cf79676 100644
--- a/webpack.config.babel.js
+++ b/webpack.config.babel.js
@@ -6,7 +6,11 @@ import ExtractTextPlugin from 'extract-text-webpack-plugin'
 import WebpackStableModuleIdAndHash from 'webpack-stable-module-id-and-hash'
 import dotenv from 'dotenv'
 
-dotenv.config()
+const dotenvError = dotenv.config().error
+
+if (dotenvError) {
+  throw dotenvError
+}
 
 const START = process.env.npm_lifecycle_event === 'start'
 const BUILD = process.env.npm_lifecycle_event === 'build'