diff --git a/.travis.yml b/.travis.yml
index e937fc1..3ae989d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,6 +18,7 @@ before_install:
 
 install:
     - composer require symfony/http-kernel:${SYMFONY_VERSION} --no-update --no-scripts --prefer-dist
+    - composer require symfony/dotenv:${SYMFONY_VERSION} --no-update --no-scripts --prefer-dist
     - composer require --dev symfony/framework-bundle:${SYMFONY_VERSION} --no-update --no-scripts --prefer-dist
     - composer update --prefer-dist
 
diff --git a/composer.json b/composer.json
index ec36bf9..d6784c0 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
 
         "behat/behat": "^3.1",
         "symfony/http-kernel": "^3.3|^4.0",
-        "symfony/dotenv": "^4.0"
+        "symfony/dotenv": "^3.3|^4.0"
     },
     "require-dev": {
         "behat/mink": "^1.7",
diff --git a/features/not_crashing_behat.feature b/features/not_crashing_behat.feature
index 1386842..7fc7f9b 100644
--- a/features/not_crashing_behat.feature
+++ b/features/not_crashing_behat.feature
@@ -67,6 +67,7 @@ Feature: Not crashing Behat
                     kernel:
                         path: src/MyKernel.php
                         class: MyKernel
+                        bootstrap: ~
         """
         And a file ".env_in_memory" containing:
         """
diff --git a/src/ServiceContainer/SymfonyExtension.php b/src/ServiceContainer/SymfonyExtension.php
index 35bdabd..10afb25 100644
--- a/src/ServiceContainer/SymfonyExtension.php
+++ b/src/ServiceContainer/SymfonyExtension.php
@@ -61,6 +61,16 @@ final class SymfonyExtension implements Extension
      */
     const SHARED_KERNEL_CONTAINER_ID = 'sylius_symfony_extension.shared_kernel.container';
 
+    /**
+     * Default symfony environment used to run your suites.
+     */
+    private const DEFAULT_ENV = 'test';
+
+    /**
+     * Enable or disable the debug mode
+     */
+    private const DEBUG_MODE = false;
+
     /**
      * @var CrossContainerProcessor|null
      */
@@ -115,10 +125,11 @@ final class SymfonyExtension implements Extension
         if (null !== $config['env_file']) {
             $this->loadEnvVars($container, $config['env_file']);
 
-            $environment = getenv('APP_ENV');
-            $config['kernel']['env'] = $environment ?? 'test';
-        } else {
-            $this->requireKernelBootstrapFile($container->getParameter('paths.base'), $config['bootstrap']);
+            $environment = false !== getenv('APP_ENV') ? getenv('APP_ENV') : self::DEFAULT_ENV;
+            $debugMode = false !== getenv('APP_DEBUG') ? getenv('APP_DEBUG') : self::DEBUG_MODE;
+
+            $config['kernel']['env'] = $environment;
+            $config['kernel']['kernel'] = $debugMode;
         }
 
         $this->loadKernel($container, $config['kernel']);
@@ -142,7 +153,7 @@ final class SymfonyExtension implements Extension
 
     /**
      * @param ContainerBuilder $container
-     * @param string           $fileName
+     * @param string $fileName
      */
     private function loadEnvVars(ContainerBuilder $container, string $fileName): void
     {
@@ -163,6 +174,8 @@ final class SymfonyExtension implements Extension
         $definition->setFile($this->getKernelFile($container->getParameter('paths.base'), $config['path']));
 
         $container->setDefinition(self::KERNEL_ID, $definition);
+
+        $this->requireKernelBootstrapFile($container->getParameter('paths.base'), $config['bootstrap']);
     }
 
     /**