diff --git a/typo3/sysext/dbal/Tests/Unit/Database/DatabaseConnectionPostgresqlTest.php b/typo3/sysext/dbal/Tests/Unit/Database/DatabaseConnectionPostgresqlTest.php
index b17b08bace72ba7db4c503a3f71e53256a1b421b..fc87af0d565ece785477a023d04f6289397d985f 100644
--- a/typo3/sysext/dbal/Tests/Unit/Database/DatabaseConnectionPostgresqlTest.php
+++ b/typo3/sysext/dbal/Tests/Unit/Database/DatabaseConnectionPostgresqlTest.php
@@ -31,6 +31,9 @@ class DatabaseConnectionPostgresqlTest extends AbstractTestCase
      */
     protected function setUp()
     {
+        if (!defined('ADODB_ASSOC_CASE')) {
+            define('ADODB_ASSOC_CASE', ADODB_ASSOC_CASE_NATIVE);
+        }
         $configuration = [
             'handlerCfg' => [
                 '_DEFAULT' => [