diff --git a/.travis.yml b/.travis.yml
index 08d5401..294799a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -35,20 +35,23 @@ matrix:
             env:
                 - PIMCORE_SKELETON_BRANCH="tags/v2.3.0"
                 - DACHCOM_TEST_SECTION=ecs
-        -   name: "Codeception Tests (Pimcore 6.0.x, Symfony ^4.0, PHP 7.3)"
+        -   name: "Codeception Tests (Pimcore 6.0.x, Symfony ^4.3, PHP 7.3)"
             sudo: required
             php: 7.3
             env:
+                - SYMFONY_VERSION="~4.3.0"
                 - PIMCORE_SKELETON_BRANCH="tags/v2.0.0"
-        -   name: "Codeception Tests (Pimcore 6.1.x, Symfony ^4.0, PHP 7.3)"
+        -   name: "Codeception Tests (Pimcore 6.1.x, Symfony ^4.3, PHP 7.3)"
             sudo: required
             php: 7.3
             env:
+                - SYMFONY_VERSION="~4.3.0"
                 - PIMCORE_SKELETON_BRANCH="tags/v2.1.0"
-        -   name: "Codeception Tests (Pimcore 6.2.x, Symfony ^4.0, PHP 7.3)"
+        -   name: "Codeception Tests (Pimcore 6.2.x, Symfony ^4.3, PHP 7.3)"
             sudo: required
             php: 7.3
             env:
+                - SYMFONY_VERSION="~4.3.0"
                 - PIMCORE_SKELETON_BRANCH="tags/v2.2.0"
         -   name: "Codeception Tests (Pimcore 6.3.x, Symfony ^4.0, PHP 7.2)"
             sudo: required
diff --git a/tests/_support/Helper/PimcoreCore.php b/tests/_support/Helper/PimcoreCore.php
index 2422244..782ac3d 100644
--- a/tests/_support/Helper/PimcoreCore.php
+++ b/tests/_support/Helper/PimcoreCore.php
@@ -214,12 +214,9 @@ protected function setConfiguration($configuration = null)
             $class = $this->getContainer()->getParameter('kernel.container_class');
             $cacheDir = $this->kernel->getCacheDir();
 
-            touch($cacheDir . '/' . $class . '.php');
+            unlink($cacheDir . '/' . $class . '.php');
         }
 
-        // otherwise cache invalidator is not detecting config changes!
-        sleep(1);
-
         $bundleName = getenv('DACHCOM_BUNDLE_NAME');
         $bundleClass = getenv('DACHCOM_BUNDLE_HOME');