diff --git a/lib/utils/createConfig.js b/lib/utils/createConfig.js
index 0211561235..3acae98545 100644
--- a/lib/utils/createConfig.js
+++ b/lib/utils/createConfig.js
@@ -72,10 +72,6 @@ function createConfig(config, argv, { port }) {
     }
   }
 
-  if (!options.filename && firstWpOpt.output && firstWpOpt.output.filename) {
-    options.filename = firstWpOpt.output && firstWpOpt.output.filename;
-  }
-
   if (!options.watchOptions && firstWpOpt.watchOptions) {
     options.watchOptions = firstWpOpt.watchOptions;
   }
diff --git a/lib/utils/normalizeOptions.js b/lib/utils/normalizeOptions.js
index 443d2df94a..35fac4896f 100644
--- a/lib/utils/normalizeOptions.js
+++ b/lib/utils/normalizeOptions.js
@@ -5,6 +5,10 @@
 */
 
 function normalizeOptions(compiler, options) {
+  const firstWpOpt = compiler.compilers
+    ? compiler.compilers[0].options
+    : compiler.options;
+
   // Setup default value
   options.contentBase =
     options.contentBase !== undefined ? options.contentBase : process.cwd();
@@ -22,6 +26,10 @@ function normalizeOptions(compiler, options) {
   if (!options.watchOptions) {
     options.watchOptions = {};
   }
+
+  if (!options.filename && firstWpOpt.output && firstWpOpt.output.filename) {
+    options.filename = firstWpOpt.output.filename;
+  }
 }
 
 module.exports = normalizeOptions;
diff --git a/test/server/utils/__snapshots__/createConfig.test.js.snap b/test/server/utils/__snapshots__/createConfig.test.js.snap
index 5549367189..cea83a193e 100644
--- a/test/server/utils/__snapshots__/createConfig.test.js.snap
+++ b/test/server/utils/__snapshots__/createConfig.test.js.snap
@@ -283,51 +283,6 @@ Object {
 }
 `;
 
-exports[`createConfig filename option (in devServer config) 1`] = `
-Object {
-  "filename": "[name]-dev-server-bundle.js",
-  "hot": true,
-  "hotOnly": false,
-  "noInfo": true,
-  "port": 8080,
-  "publicPath": "/",
-  "stats": Object {
-    "cached": false,
-    "cachedAssets": false,
-  },
-}
-`;
-
-exports[`createConfig filename option (in output config) 1`] = `
-Object {
-  "filename": "[name]-output-bundle.js",
-  "hot": true,
-  "hotOnly": false,
-  "noInfo": true,
-  "port": 8080,
-  "publicPath": "/",
-  "stats": Object {
-    "cached": false,
-    "cachedAssets": false,
-  },
-}
-`;
-
-exports[`createConfig filename option (in webpack config) 1`] = `
-Object {
-  "filename": "[name]-bundle.js",
-  "hot": true,
-  "hotOnly": false,
-  "noInfo": true,
-  "port": 8080,
-  "publicPath": "/",
-  "stats": Object {
-    "cached": false,
-    "cachedAssets": false,
-  },
-}
-`;
-
 exports[`createConfig historyApiFallback option (in devServer config) 1`] = `
 Object {
   "historyApiFallback": true,
diff --git a/test/server/utils/__snapshots__/normalizeOptions.test.js.snap b/test/server/utils/__snapshots__/normalizeOptions.test.js.snap
index 0658e08b4b..045e664fc0 100644
--- a/test/server/utils/__snapshots__/normalizeOptions.test.js.snap
+++ b/test/server/utils/__snapshots__/normalizeOptions.test.js.snap
@@ -7,6 +7,7 @@ Object {
     "/path/to/dist1",
     "/path/to/dist2",
   ],
+  "filename": "[name].js",
   "serverMode": "sockjs",
   "watchOptions": Object {},
 }
@@ -16,6 +17,79 @@ exports[`normalizeOptions contentBase string should set correct options 1`] = `
 Object {
   "clientMode": "sockjs",
   "contentBase": "/path/to/dist",
+  "filename": "[name].js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions existing devServer.filename, existing compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "devserver-bundle.js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions existing devServer.filename, no compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "devserver-bundle.js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions multi compiler, existing devServer.filename, existing compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "devserver-bundle.js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions multi compiler, existing devServer.filename, no compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "devserver-bundle.js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions multi compiler, no devServer.filename, existing compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "mybundle.js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions multi compiler, no devServer.filename, no compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "[name].js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions no devServer.filename, existing compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "mybundle.js",
+  "serverMode": "sockjs",
+  "watchOptions": Object {},
+}
+`;
+
+exports[`normalizeOptions no devServer.filename, no compiler filename should set correct options 1`] = `
+Object {
+  "clientMode": "sockjs",
+  "filename": "[name].js",
   "serverMode": "sockjs",
   "watchOptions": Object {},
 }
@@ -24,6 +98,7 @@ Object {
 exports[`normalizeOptions no options should set correct options 1`] = `
 Object {
   "clientMode": "sockjs",
+  "filename": "[name].js",
   "serverMode": "sockjs",
   "watchOptions": Object {},
 }
@@ -32,6 +107,7 @@ Object {
 exports[`normalizeOptions watchOptions should set correct options 1`] = `
 Object {
   "clientMode": "sockjs",
+  "filename": "[name].js",
   "serverMode": "sockjs",
   "watchOptions": Object {
     "poll": true,
diff --git a/test/server/utils/createConfig.test.js b/test/server/utils/createConfig.test.js
index 67431598c4..f6cc344093 100644
--- a/test/server/utils/createConfig.test.js
+++ b/test/server/utils/createConfig.test.js
@@ -276,42 +276,6 @@ describe('createConfig', () => {
     expect(config).toMatchSnapshot();
   });
 
-  it('filename option (in webpack config)', () => {
-    const config = createConfig(
-      Object.assign({}, webpackConfig, {
-        output: { filename: '[name]-bundle.js' },
-      }),
-      argv,
-      { port: 8080 }
-    );
-
-    expect(config).toMatchSnapshot();
-  });
-
-  it('filename option (in output config)', () => {
-    const config = createConfig(
-      Object.assign({}, webpackConfig, {
-        output: { filename: '[name]-output-bundle.js' },
-      }),
-      argv,
-      { port: 8080 }
-    );
-
-    expect(config).toMatchSnapshot();
-  });
-
-  it('filename option (in devServer config)', () => {
-    const config = createConfig(
-      Object.assign({}, webpackConfig, {
-        devServer: { filename: '[name]-dev-server-bundle.js' },
-      }),
-      argv,
-      { port: 8080 }
-    );
-
-    expect(config).toMatchSnapshot();
-  });
-
   it('watchOptions option (in output config)', () => {
     const config = createConfig(
       Object.assign({}, webpackConfig, {
diff --git a/test/server/utils/normalizeOptions.test.js b/test/server/utils/normalizeOptions.test.js
index c1f66f4939..62facbf013 100644
--- a/test/server/utils/normalizeOptions.test.js
+++ b/test/server/utils/normalizeOptions.test.js
@@ -37,12 +37,112 @@ describe('normalizeOptions', () => {
       },
       optionsResults: null,
     },
+    {
+      title: 'no devServer.filename, no compiler filename',
+      webpackConfig: null,
+      multiCompiler: false,
+      options: {},
+      optionsResults: null,
+    },
+    {
+      title: 'no devServer.filename, existing compiler filename',
+      webpackConfig: {
+        output: {
+          filename: 'mybundle.js',
+        },
+      },
+      multiCompiler: false,
+      options: {},
+      optionsResults: null,
+    },
+    {
+      title: 'existing devServer.filename, no compiler filename',
+      webpackConfig: null,
+      multiCompiler: false,
+      options: {
+        filename: 'devserver-bundle.js',
+      },
+      optionsResults: null,
+    },
+    {
+      title: 'existing devServer.filename, existing compiler filename',
+      webpackConfig: {
+        output: {
+          filename: 'mybundle.js',
+        },
+      },
+      multiCompiler: false,
+      options: {
+        filename: 'devserver-bundle.js',
+      },
+      optionsResults: null,
+    },
+    {
+      title: 'multi compiler, no devServer.filename, no compiler filename',
+      webpackConfig: null,
+      multiCompiler: true,
+      options: {},
+      optionsResults: null,
+    },
+    {
+      title:
+        'multi compiler, no devServer.filename, existing compiler filename',
+      webpackConfig: {
+        output: {
+          filename: 'mybundle.js',
+        },
+      },
+      multiCompiler: true,
+      options: {},
+      optionsResults: null,
+    },
+    {
+      title:
+        'multi compiler, existing devServer.filename, no compiler filename',
+      webpackConfig: null,
+      multiCompiler: true,
+      options: {
+        filename: 'devserver-bundle.js',
+      },
+      optionsResults: null,
+    },
+    {
+      title:
+        'multi compiler, existing devServer.filename, existing compiler filename',
+      webpackConfig: {
+        output: {
+          filename: 'mybundle.js',
+        },
+      },
+      multiCompiler: true,
+      options: {
+        filename: 'devserver-bundle.js',
+      },
+      optionsResults: null,
+    },
   ];
 
   cases.forEach((data) => {
     describe(data.title, () => {
       let compiler;
       beforeAll(() => {
+        // this will merge webpack configs through a depth of one layer of objects,
+        // specifically so that the webpack config output object can be merged
+        const mergeConfigs = (baseConfig, config) => {
+          Object.keys(config).forEach((key1) => {
+            if (typeof config[key1] === 'object') {
+              Object.keys(config[key1]).forEach((key2) => {
+                if (!baseConfig[key1]) {
+                  baseConfig[key1] = {};
+                }
+                baseConfig[key1][key2] = config[key1][key2];
+              });
+            } else {
+              baseConfig[key1] = config[key1];
+            }
+          });
+        };
+
         let webpackConfig;
         if (data.multiCompiler) {
           webpackConfig = require('../../fixtures/multi-compiler-config/webpack.config');
@@ -50,6 +150,13 @@ describe('normalizeOptions', () => {
           webpackConfig = require('../../fixtures/simple-config/webpack.config');
         }
 
+        if (data.webpackConfig) {
+          mergeConfigs(
+            data.multiCompiler ? webpackConfig[0] : webpackConfig,
+            data.webpackConfig
+          );
+        }
+
         compiler = webpack(webpackConfig);
       });