diff --git a/.travis.yml b/.travis.yml
index 47d5150b03..f48519f44c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -50,7 +50,7 @@ script:
   - npm run lint:all
   - npm run test:ci:all
   - npm run docs:coverage
-  - npm run build:showcase:ghpages
+  - if [[ $TRAVIS_TAG == "" && ${TRAVIS_EVENT_TYPE} != "cron" ]]; then npm run build:showcase:ghpages:test-ci-env; else npm run build:showcase:ghpages; fi
   - npm run docs:publish
   - npm run release:publish
   - bash ./scripts/ci/print-logs.sh
diff --git a/package-lock.json b/package-lock.json
index 834133f3fc..41ef16e911 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "stark-srcs",
-  "version": "10.0.0-alpha.3",
+  "version": "10.0.0-alpha.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 70d85ad1cc..30b9031f31 100644
--- a/package.json
+++ b/package.json
@@ -68,6 +68,7 @@
     "build:stark-ui": "npm run build -- --packages=stark-ui",
     "build:showcase": "cd showcase && npm run build:prod && cd ..",
     "build:showcase:ghpages": "cd showcase && npm run build:prod:ghpages && cd ..",
+    "build:showcase:ghpages:test-ci-env": "cd showcase && npm run build:prod:ghpages:test-ci-env && cd ..",
     "clean": "npx rimraf ./dist",
     "clean:all": "npm run clean && npm run clean:stark-build && npm run clean:stark-core && npm run clean:stark-ui && npm run clean:stark-testing && npm run clean:starter && npm run clean:showcase",
     "clean:stark-build": "cd packages/stark-build && npm run clean && cd ../..",
diff --git a/packages/stark-build/config/webpack.common.js b/packages/stark-build/config/webpack.common.js
index d1a1f7a0d7..49345b2b08 100644
--- a/packages/stark-build/config/webpack.common.js
+++ b/packages/stark-build/config/webpack.common.js
@@ -173,7 +173,10 @@ module.exports = options => {
 					? [
 							{
 								test: /\.js$/,
-								use: [buildOptimizerLoader]
+								use: [buildOptimizerLoader],
+								exclude: [
+									helpers.root("node_modules/prettier/parser-typescript.js")
+								]
 							}
 					  ]
 					: []),
diff --git a/packages/stark-build/config/webpack.prod.js b/packages/stark-build/config/webpack.prod.js
index 42e0e4c4bd..4060675e6e 100644
--- a/packages/stark-build/config/webpack.prod.js
+++ b/packages/stark-build/config/webpack.prod.js
@@ -23,12 +23,12 @@ const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
 const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
 const HashedModuleIdsPlugin = require("webpack/lib/HashedModuleIdsPlugin");
 
-function getUglifyOptions(supportES2015) {
+function getUglifyOptions(supportES2015, isTestCIEnv = false) {
 	const uglifyCompressOptions = {
 		pure_getters: true /* buildOptimizer */,
 		// PURE comments work best with 3 passes.
 		// See https://github.com/webpack/webpack/issues/2899#issuecomment-317425926.
-		passes: 3 /* buildOptimizer */
+		passes: isTestCIEnv ? 1 : 3 /* buildOptimizer */
 	};
 
 	return {
@@ -54,9 +54,10 @@ module.exports = function() {
 		HMR: false,
 		environment: buildUtils.DEFAULT_METADATA.E2E ? "e2e.prod" : "prod"
 	});
+	const isTestCIEnv = helpers.hasProcessFlag("test-ci-env");
 	const supportES2015 = buildUtils.supportES2015(METADATA.TS_CONFIG_PATH);
 
-	return webpackMerge(commonConfig({ ENV: ENV, metadata: METADATA }), {
+	const webpackConfig = webpackMerge(commonConfig({ ENV: ENV, metadata: METADATA }), {
 		/**
 		 * Stats lets you precisely control what bundle information gets displayed
 		 * reference: https://webpack.js.org/configuration/stats/
@@ -71,8 +72,6 @@ module.exports = function() {
 
 		mode: "production",
 
-		devtool: "source-map",
-
 		// reference: https://medium.com/webpack/webpack-4-mode-and-optimization-5423a6bc597a
 		optimization: {
 			removeAvailableModules: true,
@@ -97,8 +96,9 @@ module.exports = function() {
 				 */
 				new UglifyJsPlugin({
 					parallel: true, // use multi-process parallel running to improve the build speed (default concurrent processes: os.cpus().length - 1)
-					sourceMap: true, // useful to still be able to debug in production
-					uglifyOptions: getUglifyOptions(supportES2015)
+					sourceMap: !isTestCIEnv, // useful to still be able to debug in production
+					uglifyOptions: getUglifyOptions(supportES2015),
+					cache: true
 				}),
 				// other options than Uglify: BabelifyMinifyWebpackPlugin or ClosureCompilerPlugin
 
@@ -333,4 +333,10 @@ module.exports = function() {
 			})
 		]
 	});
+
+	if (!isTestCIEnv) {
+		webpackConfig.devtool = "source-map";
+	}
+
+	return webpackConfig;
 };
diff --git a/showcase/package.json b/showcase/package.json
index 189c793aee..36c00710cf 100644
--- a/showcase/package.json
+++ b/showcase/package.json
@@ -27,6 +27,7 @@
   },
   "scripts": {
     "build:aot:prod": "npm run clean:dist && npm run clean:aot && cross-env BUILD_AOT=1 npm run webpack -- --config node_modules/@nationalbankbelgium/stark-build/config/webpack.prod.js  --progress --profile --bail",
+    "build:aot:prod:test-ci-env": "npm run clean:dist && npm run clean:aot && cross-env BUILD_AOT=1 npm run webpack -- --config node_modules/@nationalbankbelgium/stark-build/config/webpack.prod.js  --progress --profile --bail --test-ci-env",
     "build:aot": "npm run build:aot:prod",
     "build:aot:dev": "cross-env BUILD_AOT=1 npm run build:dev",
     "build:dev": "npm run clean:dist && npm run webpack -- --config node_modules/@nationalbankbelgium/stark-build/config/webpack.dev.js --progress --profile",
@@ -34,6 +35,7 @@
     "build:docker": "npm run build:prod && docker build -t angular2-webpack-start:latest .",
     "build:prod": "npm run clean:dist && npm run build:aot:prod",
     "build:prod:ghpages": "npm run clean:dist && node ./ghpages-adapt-angular-json.js && npm run build:aot:prod",
+    "build:prod:ghpages:test-ci-env": "npm run clean:dist && node ./ghpages-adapt-angular-json.js && npm run build:aot:prod:test-ci-env",
     "build": "npm run build:dev",
     "check-deps": "npx npm-check-u",
     "ci:aot": "cross-env BUILD_E2E=1 npm run lint && npm run test && npm run build:aot && npm run e2e",