diff --git a/.env.dist b/.env
similarity index 100%
rename from .env.dist
rename to .env
diff --git a/.env.prod b/.env.prod
new file mode 100644
index 0000000000..4f53349b60
--- /dev/null
+++ b/.env.prod
@@ -0,0 +1,2 @@
+APP_DEBUG=0
+APP_SECRET='s$cretf0rt3st'
diff --git a/.env.prod.dist b/.env.prod.dist
deleted file mode 100644
index 16f0780758..0000000000
--- a/.env.prod.dist
+++ /dev/null
@@ -1,23 +0,0 @@
-# This file is a "template" of which env vars needs to be defined in your configuration or in an .env file
-# Set variables here that may be different on each deployment target of the app, e.g. development, staging, production.
-# https://symfony.com/doc/current/best_practices/configuration.html#infrastructure-related-configuration
-
-###> symfony/framework-bundle ###
-APP_ENV=prod
-APP_DEBUG=0
-APP_SECRET=EDITME
-###< symfony/framework-bundle ###
-
-###> doctrine/doctrine-bundle ###
-# Format described at http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url
-# For a sqlite database, use: "sqlite:///%kernel.project_dir%/var/data.db"
-# Set "serverVersion" to your server version to avoid edge-case exceptions and extra database calls
-DATABASE_URL=mysql://root@127.0.0.1/sylius_%kernel.environment%
-###< doctrine/doctrine-bundle ###
-
-###> symfony/swiftmailer-bundle ###
-# For Gmail as a transport, use: "gmail://username:password@localhost"
-# For a generic SMTP server, use: "smtp://localhost:25?encryption=&auth_mode="
-# Delivery is disabled by default via "null://localhost"
-MAILER_URL=smtp://localhost
-###< symfony/swiftmailer-bundle ###
diff --git a/.env.test b/.env.test
new file mode 100644
index 0000000000..1556a53206
--- /dev/null
+++ b/.env.test
@@ -0,0 +1,3 @@
+APP_SECRET='s$cretf0rt3st'
+
+KERNEL_CLASS='App\Kernel'
diff --git a/.env.test.dist b/.env.test.dist
deleted file mode 100644
index 919b4ad083..0000000000
--- a/.env.test.dist
+++ /dev/null
@@ -1,23 +0,0 @@
-# This file is a "template" of which env vars needs to be defined in your configuration or in an .env file
-# Set variables here that may be different on each deployment target of the app, e.g. development, staging, production.
-# https://symfony.com/doc/current/best_practices/configuration.html#infrastructure-related-configuration
-
-###> symfony/framework-bundle ###
-APP_ENV=test
-APP_DEBUG=1
-APP_SECRET=EDITME
-###< symfony/framework-bundle ###
-
-###> doctrine/doctrine-bundle ###
-# Format described at http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url
-# For a sqlite database, use: "sqlite:///%kernel.project_dir%/var/data.db"
-# Set "serverVersion" to your server version to avoid edge-case exceptions and extra database calls
-DATABASE_URL=mysql://root@127.0.0.1/sylius_%kernel.environment%
-###< doctrine/doctrine-bundle ###
-
-###> symfony/swiftmailer-bundle ###
-# For Gmail as a transport, use: "gmail://username:password@localhost"
-# For a generic SMTP server, use: "smtp://localhost:25?encryption=&auth_mode="
-# Delivery is disabled by default via "null://localhost"
-MAILER_URL=null://localhost
-###< symfony/swiftmailer-bundle ###
diff --git a/.env.test_cached b/.env.test_cached
new file mode 100644
index 0000000000..dc9cf85b70
--- /dev/null
+++ b/.env.test_cached
@@ -0,0 +1,4 @@
+APP_DEBUG=0
+APP_SECRET='s$cretf0rt3st'
+
+KERNEL_CLASS='App\Kernel'
diff --git a/.env.test_cached.dist b/.env.test_cached.dist
deleted file mode 100644
index 9788dd0749..0000000000
--- a/.env.test_cached.dist
+++ /dev/null
@@ -1,23 +0,0 @@
-# This file is a "template" of which env vars needs to be defined in your configuration or in an .env file
-# Set variables here that may be different on each deployment target of the app, e.g. development, staging, production.
-# https://symfony.com/doc/current/best_practices/configuration.html#infrastructure-related-configuration
-
-###> symfony/framework-bundle ###
-APP_ENV=test_cached
-APP_DEBUG=0
-APP_SECRET=EDITME
-###< symfony/framework-bundle ###
-
-###> doctrine/doctrine-bundle ###
-# Format described at http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url
-# For a sqlite database, use: "sqlite:///%kernel.project_dir%/var/data.db"
-# Set "serverVersion" to your server version to avoid edge-case exceptions and extra database calls
-DATABASE_URL=mysql://root@127.0.0.1/sylius_${APP_ENV}
-###< doctrine/doctrine-bundle ###
-
-###> symfony/swiftmailer-bundle ###
-# For Gmail as a transport, use: "gmail://username:password@localhost"
-# For a generic SMTP server, use: "smtp://localhost:25?encryption=&auth_mode="
-# Delivery is disabled by default via "null://localhost"
-MAILER_URL=null://localhost
-###< symfony/swiftmailer-bundle ###
diff --git a/.gitignore b/.gitignore
index fbeae651e4..37184004ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,13 +1,8 @@
-/var/*
-!/var/.gitignore
-
 /public/assets
-/public/bundles
 /public/css
 /public/js
 /public/media
 
-/vendor
 /node_modules
 
 /etc/build/*
@@ -16,16 +11,19 @@
 /behat.yml
 /phpspec.yml
 
-/.env
-/.env.prod
-/.env.staging
-/.env.test
-/.env.test_cached
-
 /docker-compose.override.yaml
 /docker-compose.override.yml
 /docker/mysql/data/
 
+###> symfony/framework-bundle ###
+/.env.*.local
+/.env.local
+/.env.local.php
+/public/bundles
+/var/
+/vendor/
+###< symfony/framework-bundle ###
+
 ###> symfony/web-server-bundle ###
 /.web-server-pid
 ###< symfony/web-server-bundle ###
diff --git a/.travis.yml b/.travis.yml
index 2acd5af2e9..0607f68955 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,10 @@ dist: trusty
 php:
     - 7.2
 
+env:
+    global:
+        - APP_ENV=test_cached
+
 jobs:
     include:
         -   &test
@@ -31,20 +35,17 @@ jobs:
                 - echo "memory_limit=4096M" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
                 - echo "extension = memcached.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
 
-                - cp .env.test_cached.dist .env.test_cached
-                - set -a && source .env.test_cached && set +a
-
             install:
                 - if [ ! -z "${SYMFONY_VERSION}" ]; then bin/require-symfony-version composer.json "${SYMFONY_VERSION}"; fi
                 - composer update --no-interaction --prefer-dist
                 - yarn install
 
             before_script:
-                - bin/console doctrine:database:create --env=test_cached -vvv # Have to be run with debug = true, to omit generating proxies before setting up the database
-                - bin/console cache:warmup --env=test_cached --no-debug -vvv
-                - bin/console doctrine:migrations:migrate --no-interaction --env=test_cached --no-debug -vvv
+                - APP_DEBUG=1 bin/console doctrine:database:create -vvv # Have to be run with debug = true, to omit generating proxies before setting up the database
+                - bin/console cache:warmup -vvv
+                - bin/console doctrine:migrations:migrate --no-interaction -vvv
 
-                - bin/console assets:install public --env=test_cached --no-debug -vvv
+                - bin/console assets:install public -vvv
                 - yarn build
 
                 # Configure display
@@ -74,7 +75,7 @@ jobs:
                 - java -Dwebdriver.chrome.driver=$SYLIUS_CACHE_DIR/chromedriver -jar $SYLIUS_CACHE_DIR/selenium.jar > /dev/null 2>&1 &
 
                 # Run webserver
-                - bin/console server:run localhost:8080 -d public --env=test_cached --no-debug --quiet > /dev/null 2>&1 &
+                - bin/console server:run localhost:8080 -d public --quiet > /dev/null 2>&1 &
 
             script:
                 - composer validate --strict
@@ -85,7 +86,7 @@ jobs:
 
                 - vendor/bin/phpspec run --no-interaction -f dot
 
-                - bin/console sylius:fixtures:load --no-interaction --env=test_cached --no-debug -vvv
+                - bin/console sylius:fixtures:load --no-interaction -vvv
 
                 - echo "Testing (Behat, without javascript scenarios; ~@javascript && ~@todo && ~@cli)" "Sylius"
                 - vendor/bin/behat --strict --no-interaction -vvv -f progress --tags="~@javascript && ~@todo && ~@cli"
@@ -99,9 +100,9 @@ jobs:
 
         -   <<: *test
 
-            name: "Symfony 4.1.* build"
+            name: "Symfony 4.2.* build"
 
-            env: SYMFONY_VERSION="4.1.*" SYLIUS_CACHE_DIR=$HOME/.sylius-cache SYLIUS_BUILD_DIR=etc/build
+            env: SYMFONY_VERSION="4.2.*" SYLIUS_CACHE_DIR=$HOME/.sylius-cache SYLIUS_BUILD_DIR=etc/build
 
         -
             stage: test
diff --git a/Dockerfile b/Dockerfile
index e6adaf02e4..88546cd124 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -83,6 +83,7 @@ RUN set -eux; \
 	composer clear-cache
 
 # copy only specifically what we need
+COPY .env .env.prod .env.test .env.test_cached ./
 COPY bin bin/
 COPY config config/
 COPY public public/
diff --git a/bin/console b/bin/console
index 2d1d067c49..52fd3989fb 100755
--- a/bin/console
+++ b/bin/console
@@ -1,36 +1,31 @@
 #!/usr/bin/env php
 <?php
 
-declare(strict_types=1);
-
 use App\Kernel;
 use Symfony\Bundle\FrameworkBundle\Console\Application;
 use Symfony\Component\Console\Input\ArgvInput;
 use Symfony\Component\Debug\Debug;
-use Symfony\Component\Dotenv\Dotenv;
 
 set_time_limit(0);
 
-require __DIR__.'/../vendor/autoload.php';
+require dirname(__DIR__).'/vendor/autoload.php';
 
 if (!class_exists(Application::class)) {
-    throw new \RuntimeException('You need to add "symfony/framework-bundle" as a Composer dependency.');
+    throw new RuntimeException('You need to add "symfony/framework-bundle" as a Composer dependency.');
 }
 
-if (!isset($_SERVER['APP_ENV'])) {
-    if (!class_exists(Dotenv::class)) {
-        throw new \RuntimeException('APP_ENV environment variable is not defined. You need to define environment variables for configuration or add "symfony/dotenv" as a Composer dependency to load variables from a .env file.');
-    }
+$input = new ArgvInput();
+if (null !== $env = $input->getParameterOption(['--env', '-e'], null, true)) {
+    putenv('APP_ENV='.$_SERVER['APP_ENV'] = $_ENV['APP_ENV'] = $env);
+}
 
-    $envFile = file_exists(__DIR__.'/../.env') ? __DIR__.'/../.env' : __DIR__.'/../.env.dist';
-    (new Dotenv())->load($envFile);
+if ($input->hasParameterOption('--no-debug', true)) {
+    putenv('APP_DEBUG='.$_SERVER['APP_DEBUG'] = $_ENV['APP_DEBUG'] = '0');
 }
 
-$input = new ArgvInput();
-$env = $input->getParameterOption(['--env', '-e'], $_SERVER['APP_ENV'] ?? 'dev', true);
-$debug = (bool) ($_SERVER['APP_DEBUG'] ?? ('prod' !== $env)) && !$input->hasParameterOption('--no-debug', true);
+require dirname(__DIR__).'/config/bootstrap.php';
 
-if ($debug) {
+if ($_SERVER['APP_DEBUG']) {
     umask(0000);
 
     if (class_exists(Debug::class)) {
@@ -38,6 +33,6 @@ if ($debug) {
     }
 }
 
-$kernel = new Kernel($env, $debug);
+$kernel = new Kernel($_SERVER['APP_ENV'], (bool) $_SERVER['APP_DEBUG']);
 $application = new Application($kernel);
 $application->run($input);
diff --git a/bin/require-symfony-version b/bin/require-symfony-version
index 8d7beafeeb..d8f6a961ca 100755
--- a/bin/require-symfony-version
+++ b/bin/require-symfony-version
@@ -13,7 +13,6 @@ $packages = [
     'symfony/dependency-injection',
     'symfony/doctrine-bridge',
     'symfony/dom-crawler',
-    'symfony/dotenv',
     'symfony/event-dispatcher',
     'symfony/expression-language',
     'symfony/filesystem',
diff --git a/composer.json b/composer.json
index 65ed2baa17..1edaca7568 100644
--- a/composer.json
+++ b/composer.json
@@ -40,7 +40,7 @@
         "sylius-labs/coding-standard": "^2.0",
         "symfony/browser-kit": "^3.4|^4.1",
         "symfony/debug-bundle": "^3.4|^4.1",
-        "symfony/dotenv": "^3.4|^4.1",
+        "symfony/dotenv": "^4.2",
         "symfony/intl": "^3.4|^4.1",
         "symfony/web-profiler-bundle": "^3.4|^4.1",
         "symfony/web-server-bundle": "^3.4|^4.1"
@@ -54,7 +54,8 @@
     "autoload-dev": {
         "psr-4": {
             "App\\Tests\\": "tests/"
-        }
+        },
+        "classmap": ["src/Kernel.php"]
     },
     "scripts": {
         "auto-scripts": {
diff --git a/composer.lock b/composer.lock
index 89d1673176..c27ef1dee7 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "ac6d91c568fd7c0fbfd8639984e1b9ec",
+    "content-hash": "47bdcb78c73375605723aa3a98d13b39",
     "packages": [
         {
             "name": "behat/transliterator",
diff --git a/config/bootstrap.php b/config/bootstrap.php
new file mode 100644
index 0000000000..f6afb40429
--- /dev/null
+++ b/config/bootstrap.php
@@ -0,0 +1,21 @@
+<?php
+
+use Symfony\Component\Dotenv\Dotenv;
+
+require dirname(__DIR__).'/vendor/autoload.php';
+
+// Load cached env vars if the .env.local.php file exists
+// Run "composer dump-env prod" to create it (requires symfony/flex >=1.2)
+if (is_array($env = @include dirname(__DIR__).'/.env.local.php')) {
+    $_SERVER += $env;
+    $_ENV += $env;
+} elseif (!class_exists(Dotenv::class)) {
+    throw new RuntimeException('Please run "composer require symfony/dotenv" to load the ".env" files configuring the application.');
+} else {
+    // load all the .env files
+    (new Dotenv())->loadEnv(dirname(__DIR__).'/.env');
+}
+
+$_SERVER['APP_ENV'] = $_ENV['APP_ENV'] = ($_SERVER['APP_ENV'] ?? $_ENV['APP_ENV'] ?? null) ?: 'dev';
+$_SERVER['APP_DEBUG'] = $_SERVER['APP_DEBUG'] ?? $_ENV['APP_DEBUG'] ?? 'prod' !== $_SERVER['APP_ENV'];
+$_SERVER['APP_DEBUG'] = $_ENV['APP_DEBUG'] = (int) $_SERVER['APP_DEBUG'] || filter_var($_SERVER['APP_DEBUG'], FILTER_VALIDATE_BOOLEAN) ? '1' : '0';
diff --git a/public/index.php b/public/index.php
index ff75735978..e30f90c035 100644
--- a/public/index.php
+++ b/public/index.php
@@ -1,42 +1,26 @@
 <?php
 
-declare(strict_types=1);
-
 use App\Kernel;
 use Symfony\Component\Debug\Debug;
-use Symfony\Component\Dotenv\Dotenv;
 use Symfony\Component\HttpFoundation\Request;
 
-require __DIR__.'/../vendor/autoload.php';
-
-// The check is to ensure we don't use .env in production
-if (!isset($_SERVER['APP_ENV']) && !isset($_ENV['APP_ENV'])) {
-    if (!class_exists(Dotenv::class)) {
-        throw new \RuntimeException('APP_ENV environment variable is not defined. You need to define environment variables for configuration or add "symfony/dotenv" as a Composer dependency to load variables from a .env file.');
-    }
-
-    $envFile = file_exists(__DIR__.'/../.env') ? __DIR__.'/../.env' : __DIR__.'/../.env.dist';
-    (new Dotenv())->load($envFile);
-}
-
-$env = $_SERVER['APP_ENV'] ?? $_ENV['APP_ENV'] ?? 'dev';
-$debug = (bool) ($_SERVER['APP_DEBUG'] ?? $_ENV['APP_DEBUG'] ?? ('prod' !== $env));
+require dirname(__DIR__).'/config/bootstrap.php';
 
-if ($debug) {
+if ($_SERVER['APP_DEBUG']) {
     umask(0000);
 
     Debug::enable();
 }
 
-if ($trustedProxies = $_SERVER['TRUSTED_PROXIES'] ?? false) {
+if ($trustedProxies = $_SERVER['TRUSTED_PROXIES'] ?? $_ENV['TRUSTED_PROXIES'] ?? false) {
     Request::setTrustedProxies(explode(',', $trustedProxies), Request::HEADER_X_FORWARDED_ALL ^ Request::HEADER_X_FORWARDED_HOST);
 }
 
-if ($trustedHosts = $_SERVER['TRUSTED_HOSTS'] ?? false) {
-    Request::setTrustedHosts(explode(',', $trustedHosts));
+if ($trustedHosts = $_SERVER['TRUSTED_HOSTS'] ?? $_ENV['TRUSTED_HOSTS'] ?? false) {
+    Request::setTrustedHosts([$trustedHosts]);
 }
 
-$kernel = new Kernel($env, $debug);
+$kernel = new Kernel($_SERVER['APP_ENV'], (bool) $_SERVER['APP_DEBUG']);
 $request = Request::createFromGlobals();
 $response = $kernel->handle($request);
 $response->send();