diff --git a/tests/phpunit/tests/admin/wpAutomaticUpdater.php b/tests/phpunit/tests/admin/wpAutomaticUpdater.php
index 203a386df6..c702d20f76 100644
--- a/tests/phpunit/tests/admin/wpAutomaticUpdater.php
+++ b/tests/phpunit/tests/admin/wpAutomaticUpdater.php
@@ -610,7 +610,7 @@ public function test_is_allowed_dir_should_return_true_if_open_basedir_is_set_an
 
 		$open_basedir_backup = ini_get( 'open_basedir' );
 		// Allow access to the directory one level above the repository.
-		ini_set( 'open_basedir', wp_normalize_path( $abspath_grandparent ) );
+		ini_set( 'open_basedir', sys_get_temp_dir() . PATH_SEPARATOR . wp_normalize_path( $abspath_grandparent ) );
 
 		// Checking an allowed directory should succeed.
 		$actual = self::$updater->is_allowed_dir( wp_normalize_path( ABSPATH ) );
@@ -645,7 +645,7 @@ public function test_is_allowed_dir_should_return_false_if_open_basedir_is_set_a
 
 		$open_basedir_backup = ini_get( 'open_basedir' );
 		// Allow access to the directory one level above the repository.
-		ini_set( 'open_basedir', wp_normalize_path( $abspath_grandparent ) );
+		ini_set( 'open_basedir', sys_get_temp_dir() . PATH_SEPARATOR . wp_normalize_path( $abspath_grandparent ) );
 
 		// Checking a directory not within the allowed path should trigger an `open_basedir` warning.
 		$actual = self::$updater->is_allowed_dir( '/.git' );