diff --git a/lib/karma-webpack.js b/lib/karma-webpack.js
index ed10f58..ea8221a 100644
--- a/lib/karma-webpack.js
+++ b/lib/karma-webpack.js
@@ -2,6 +2,7 @@ const path = require('path');
 const fs = require('fs');
 
 const glob = require('glob');
+const minimatch = require('minimatch');
 
 const { KarmaWebpackController } = require('./KarmaWebpackController');
 
@@ -36,21 +37,35 @@ function registerExtraWebpackFiles(config, _controller) {
   });
 }
 
-function preprocessorsToWebpackEntries(preprocessors) {
+function configToWebpackEntries(config) {
   const filteredPatterns = [];
+  const { preprocessors } = config;
+
+  let files = [];
+  config.files.forEach(fileEntry => {
+    files = [...files, ...glob.sync(fileEntry.pattern)];
+  });
+
   Object.keys(preprocessors).forEach((pattern) => {
     if (preprocessors[pattern].includes('webpack')) {
       filteredPatterns.push(pattern);
     }
   });
 
-  const webpackEntries = {};
-  filteredPatterns.forEach((pattern) => {
-    const files = glob.sync(pattern);
-    files.forEach((filePath) => {
-      webpackEntries[path.parse(filePath).name] = filePath;
+  const filteredFiles = [];
+  files.forEach(filePath => {
+    filteredPatterns.forEach((pattern) => {
+      if (minimatch(filePath, pattern)) {
+        filteredFiles.push(filePath);
+      }
     });
   });
+
+  const webpackEntries = {};
+  filteredFiles.forEach((filePath) => {
+    webpackEntries[path.parse(filePath).name] = filePath;
+  });
+
   return webpackEntries;
 }
 
@@ -58,7 +73,7 @@ function preprocessorFactory(config, emitter) {
   // one time setup
   if (controller.isActive === false) {
     controller.updateWebpackOptions({
-      entry: preprocessorsToWebpackEntries(config.preprocessors),
+      entry: configToWebpackEntries(config),
       watch: config.autoWatch,
     });
     controller.updateWebpackOptions(config.webpack);
@@ -80,4 +95,5 @@ module.exports = {
   'preprocessor:webpack': ['factory', preprocessorFactory],
   'framework:webpack': ['factory', registerExtraWebpackFiles],
   registerExtraWebpackFiles,
+  configToWebpackEntries,
 };
diff --git a/package-lock.json b/package-lock.json
index f0c3d72..cfd94af 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -923,7 +923,6 @@
       "resolved": "https://registry.npmjs.org/align-text/-/align-text-0.1.4.tgz",
       "integrity": "sha1-DNkKVhCT810KmSVsIrcGlDP60Rc=",
       "dev": true,
-      "optional": true,
       "requires": {
         "kind-of": "^3.0.2",
         "longest": "^1.0.1",
@@ -1332,15 +1331,13 @@
           "version": "1.0.0",
           "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-1.0.0.tgz",
           "integrity": "sha1-rEaBd8SUNAWgkvyPKXYMb/xiBsA=",
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "is-glob": {
           "version": "2.0.1",
           "resolved": "https://registry.npmjs.org/is-glob/-/is-glob-2.0.1.tgz",
           "integrity": "sha1-0Jb5JqPe1WAPP9/ZEZjLCIjC2GM=",
           "dev": true,
-          "optional": true,
           "requires": {
             "is-extglob": "^1.0.0"
           }
@@ -6033,8 +6030,7 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -6055,14 +6051,12 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -6077,20 +6071,17 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -6207,8 +6198,7 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "ini": {
           "version": "1.3.5",
@@ -6220,7 +6210,6 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -6235,7 +6224,6 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -6243,14 +6231,12 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "minipass": {
           "version": "2.2.4",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -6269,7 +6255,6 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -6350,8 +6335,7 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -6363,7 +6347,6 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -6449,8 +6432,7 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -6486,7 +6468,6 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -6506,7 +6487,6 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -6550,14 +6530,12 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         }
       }
     },
@@ -10952,8 +10930,7 @@
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/longest/-/longest-1.0.1.tgz",
       "integrity": "sha1-MKCy2jj3N3DoKUoNIuZiXtd9AJc=",
-      "dev": true,
-      "optional": true
+      "dev": true
     },
     "loose-envify": {
       "version": "1.3.1",
diff --git a/package.json b/package.json
index fe74cbf..716f6e9 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,7 @@
   },
   "dependencies": {
     "glob": "^7.1.3",
+    "minimatch": "^3.0.4",
     "webpack-merge": "^4.1.5"
   },
   "devDependencies": {