diff --git a/karma.conf.js b/karma.conf.js
index 9d79e9e..0fdc36c 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -32,16 +32,16 @@ module.exports = function(config) {
 
     webpack: {
       module: {
-       preLoaders: [
-         { test: /\.jsx?$/, loader: 'isparta', exclude: /\/(spec|node_modules)\// },
-         { test: /\.jsx?$/, loader: 'eslint', exclude: /(node_modules)/ }
-       ],
-       loaders: [
-         { test: /\.jsx?$/, loader: 'babel', exclude: /(node_modules)/ },
-         { test: /\.css$/, loaders: ['style', 'css'], exclude: /(node_modules)/ },
-         { test: /\.scss$/, loaders: ['style', 'css', 'sass'], exclude: /(node_modules)/ }
-       ]
-     }
+        preLoaders: [
+          { test: /\.jsx?$/, loader: 'isparta', exclude: /\/(spec|node_modules)\// },
+          { test: /\.jsx?$/, loader: 'eslint', exclude: /(node_modules)/ }
+        ],
+        loaders: [
+          { test: /\.jsx?$/, loader: 'babel', exclude: /(node_modules)/ },
+          { test: /\.css$/, loaders: ['style', 'css'], exclude: /(node_modules)/ },
+          { test: /\.scss$/, loaders: ['style', 'css', 'sass'], exclude: /(node_modules)/ }
+        ]
+      }
     },
 
 
@@ -80,5 +80,5 @@ module.exports = function(config) {
     // Continuous Integration mode
     // if true, Karma captures browsers, runs the tests and exits
     singleRun: false
-  })
-}
+  });
+};
diff --git a/spec/section_spec.js b/spec/section_spec.js
index cba9e5a..a509b5b 100644
--- a/spec/section_spec.js
+++ b/spec/section_spec.js
@@ -1,8 +1,8 @@
 import 'core-js/es5';
 import React from 'react/addons';
-import Section from '../src/book/section.jsx'
-import Heading from '../src/book/heading.jsx'
-import Description from '../src/book/description.jsx'
+import Section from '../src/book/section.jsx'; // eslint-disable-line no-unused-vars
+import Heading from '../src/book/heading.jsx';
+import Description from '../src/book/description.jsx';
 
 describe('Section', function() {
   let sectionComponent;
@@ -15,25 +15,25 @@ describe('Section', function() {
     sectionComponent = shallowRenderer.getRenderOutput();
   });
 
-  it('is wrapped in <section> element',function() {
+  it('is wrapped in <section> element', function() {
     expect( sectionComponent.type ).to.equal( 'section' );
   });
 
-  describe('checks if children exist regardless of their order',function() {
+  describe('checks if children exist regardless of their order', function() {
     let children;
 
     before(function() {
       children = sectionComponent.props.children;
     });
 
-    it('includes Heading component',function() {
+    it('includes Heading component', function() {
       let childHeading = children.filter(
         component => component.type === Heading
       );
       expect( childHeading.length ).to.be.ok;
     });
 
-    it('includes Description component',function() {
+    it('includes Description component', function() {
       let childDescription = children.filter(
         component => component.type === Description
       );
@@ -42,7 +42,7 @@ describe('Section', function() {
   });
 
   // An alternative to the two tests above
-  it('includes Heading and Description components in particular order',function() {
+  it('includes Heading and Description components in particular order', function() {
     expect( sectionComponent.props.children ).to.eql( [
       <Heading />,
       <Description />
diff --git a/src/book/section.jsx b/src/book/section.jsx
index 6981a2e..746a2da 100644
--- a/src/book/section.jsx
+++ b/src/book/section.jsx
@@ -1,6 +1,6 @@
 import React from 'react';
-import Heading from './heading.jsx';
-import Description from './description.jsx';
+import Heading from './heading.jsx'; // eslint-disable-line no-unused-vars
+import Description from './description.jsx'; // eslint-disable-line no-unused-vars
 
 export default class extends React.Component {
   render() {
@@ -9,6 +9,6 @@ export default class extends React.Component {
         <Heading />
         <Description />
       </section>
-    )
+    );
   }
 }
diff --git a/webpack-dev-server.js b/webpack-dev-server.js
index e2d8567..d0038dd 100644
--- a/webpack-dev-server.js
+++ b/webpack-dev-server.js
@@ -7,10 +7,10 @@ new WebpackDevServer(webpack(config), {
   hot: true,
   headers: { 'Access-Control-Allow-Origin': '*' },
   historyApiFallback: true
-}).listen(5000, 'localhost', function (err, result) {
-  if (err) {
-    console.log(err);
+}).listen(5000, 'localhost', function(error) {
+  if (error) {
+    console.log(error);
   }
 
   console.log('Listening at localhost:5000');
-});
\ No newline at end of file
+});