diff --git a/karma.conf.js b/karma.conf.js
index e60364e3..6a2b5a9c 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -15,7 +15,7 @@ module.exports = function(config) {
 
     // list of files / patterns to load in the browser
     files: [
-      'webpack.tests.js'
+      'test/specs/**/*.spec.js'
     ],
 
 
@@ -28,17 +28,27 @@ module.exports = function(config) {
     // preprocess matching files before serving them to the browser
     // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
     preprocessors: {
-      'webpack.tests.js': ['webpack', 'sourcemap', 'coverage']
+      'test/specs/**/*.spec.js': ['webpack', 'sourcemap']
     },
 
 
     webpack: {
+      cache: true,
+      devtool: 'inline-source-map',
+      module: {
+        postLoaders: [
+          {
+            test: /\.js$/,
+            exclude: /(node_modules|test)/,
+            loader: 'istanbul-instrumenter'
+          }
+        ]
+      },
       externals: [
         {
           './adapters/http': 'var undefined'
         }
-      ],
-      devtool: 'inline-source-map'
+      ]
     },
 
     webpackServer: {
diff --git a/package.json b/package.json
index 9ef8de4c..d7c81322 100644
--- a/package.json
+++ b/package.json
@@ -40,6 +40,7 @@
     "grunt-ts": "5.0.0-beta.5",
     "grunt-update-json": "0.2.1",
     "grunt-webpack": "1.0.11",
+    "istanbul-instrumenter-loader": "^0.1.3",
     "jasmine-core": "2.3.4",
     "karma": "0.13.10",
     "karma-coverage": "0.5.2",
diff --git a/webpack.tests.js b/webpack.tests.js
deleted file mode 100644
index ed890d02..00000000
--- a/webpack.tests.js
+++ /dev/null
@@ -1,2 +0,0 @@
-var context = require.context('./test/specs', true, /\.js$/);
-context.keys().forEach(context);