diff --git a/tests/phpunit/bootstrap.php b/tests/phpunit/bootstrap.php
index 2f874f12116..3819662a5b1 100644
--- a/tests/phpunit/bootstrap.php
+++ b/tests/phpunit/bootstrap.php
@@ -53,7 +53,7 @@ define( 'MW_ENTRY_POINT', 'cli' );
 $IP = realpath( __DIR__ . '/../../' );
 // We don't use a settings file here but some code still assumes that one exists
 wfRequireOnceInGlobalScope( "$IP/includes/BootstrapHelperFunctions.php" );
-define( 'MW_CONFIG_FILE', wfDetectLocalSettingsFile( $IP ) );
+wfDetectLocalSettingsFile( $IP );
 
 // these variables must be defined before setup runs
 $GLOBALS['IP'] = $IP;
diff --git a/tests/phpunit/phpunit.php b/tests/phpunit/phpunit.php
index 6f79eb8f884..f643767795a 100755
--- a/tests/phpunit/phpunit.php
+++ b/tests/phpunit/phpunit.php
@@ -183,9 +183,7 @@ require_once "$IP/includes/BootstrapHelperFunctions.php";
 
 $wrapper = new PHPUnitMaintClass();
 $wrapper->setup();
-
-// Define how settings are loaded (e.g. LocalSettings.php)
-define( 'MW_CONFIG_FILE', $wrapper->loadSettings() );
+$wrapper->loadSettings();
 
 function wfPHPUnitSetup() {
 	// phpcs:ignore MediaWiki.NamingConventions.ValidGlobalName.allowedPrefix