diff --git a/lib/config-generator.js b/lib/config-generator.js
index d97af7ca..83bdeb71 100644
--- a/lib/config-generator.js
+++ b/lib/config-generator.js
@@ -100,7 +100,7 @@ class ConfigGenerator {
     buildRulesConfig() {
         const cssLoaders = [
             {
-                loader: 'css-loader' + this.getSourceMapOption(),
+                loader: 'css-loader' + this.getSourceMapOption() + (this.webpackConfig.isProduction() ? '?minimize=1' : ''),
             },
         ];
         if (this.webpackConfig.usePostCssLoader) {
@@ -292,7 +292,6 @@ class ConfigGenerator {
          * https://github.com/jtangelder/sass-loader/issues/285
          */
         plugins.push(new webpack.LoaderOptionsPlugin({
-            minimize: this.webpackConfig.isProduction(),
             debug: !this.webpackConfig.isProduction(),
             options: {
                 context: this.webpackConfig.getContext(),
diff --git a/test/config-generator.js b/test/config-generator.js
index 33be7c39..bb0f6483 100644
--- a/test/config-generator.js
+++ b/test/config-generator.js
@@ -221,7 +221,6 @@ describe('The config-generator function', () => {
             const actualConfig = configGenerator(config);
 
             const loaderOptionsPlugin = findPlugin(webpack.LoaderOptionsPlugin, actualConfig.plugins);
-            expect(loaderOptionsPlugin.options.minimize).to.equal(false);
             expect(loaderOptionsPlugin.options.debug).to.equal(true);
             expect(loaderOptionsPlugin.options.options.context).to.equal('/tmp/context');
             expect(loaderOptionsPlugin.options.options.output.path).to.equal('/tmp/output/public-path');
@@ -242,7 +241,6 @@ describe('The config-generator function', () => {
             const actualConfig = configGenerator(config);
 
             const loaderOptionsPlugin = findPlugin(webpack.LoaderOptionsPlugin, actualConfig.plugins);
-            expect(loaderOptionsPlugin.options.minimize).to.equal(true);
             expect(loaderOptionsPlugin.options.debug).to.equal(false);
 
             const moduleHashedIdsPlugin = findPlugin(webpack.HashedModuleIdsPlugin, actualConfig.plugins);
diff --git a/test/functional.js b/test/functional.js
index b942fd93..7087bba3 100644
--- a/test/functional.js
+++ b/test/functional.js
@@ -414,6 +414,7 @@ describe('Functional tests using webpack', function() {
             const config = createWebpackConfig('www/build', 'production');
             config.setPublicPath('/build');
             config.addEntry('main', ['./js/no_require']);
+            config.addEntry('styles', './css/h1_style.css');
 
             testSetup.runWebpack(config, (webpackAssert) => {
                 // the comment should not live in the file
@@ -421,6 +422,11 @@ describe('Functional tests using webpack', function() {
                     'main.js',
                     '// comments in no_require.js'
                 );
+                // extra spaces should not live in the CSS file
+                webpackAssert.assertOutputFileDoesNotContain(
+                    'styles.css',
+                    '    font-size: 50px;'
+                );
 
                 done();
             });