diff --git a/tests/phpunit/includes/bootstrap.php b/tests/phpunit/includes/bootstrap.php
index ed0a35bc66..dcde8fd2ea 100644
--- a/tests/phpunit/includes/bootstrap.php
+++ b/tests/phpunit/includes/bootstrap.php
@@ -97,7 +97,10 @@ if ( file_exists( DIR_TESTDATA . '/themedir1' ) ) {
 }
 
 if ( '1' !== getenv( 'WP_TESTS_SKIP_INSTALL' ) ) {
-	system( WP_PHP_BINARY . ' ' . escapeshellarg( __DIR__ . '/install.php' ) . ' ' . escapeshellarg( $config_file_path ) . ' ' . $multisite, $retval );
+	$core_tests = ( defined( 'WP_RUN_CORE_TESTS' ) && WP_RUN_CORE_TESTS ) ? 'run_core_tests' : 'no_core_tests';
+	$ms_tests   = $multisite ? 'run_ms_tests' : 'no_ms_tests';
+
+	system( WP_PHP_BINARY . ' ' . escapeshellarg( __DIR__ . '/install.php' ) . ' ' . escapeshellarg( $config_file_path ) . ' ' . $ms_tests . ' ' . $core_tests, $retval );
 	if ( 0 !== $retval ) {
 		exit( $retval );
 	}
diff --git a/tests/phpunit/includes/install.php b/tests/phpunit/includes/install.php
index cad83c7414..4ab457f48a 100644
--- a/tests/phpunit/includes/install.php
+++ b/tests/phpunit/includes/install.php
@@ -7,7 +7,11 @@
 error_reporting( E_ALL & ~E_DEPRECATED & ~E_STRICT );
 
 $config_file_path = $argv[1];
-$multisite        = ! empty( $argv[2] );
+$multisite        = in_array( 'run_ms_tests', $argv, true );
+
+if ( ! defined( 'WP_RUN_CORE_TESTS' ) && in_array( 'run_core_tests', $argv, true ) ) {
+	define( 'WP_RUN_CORE_TESTS', true );
+}
 
 define( 'WP_INSTALLING', true );
 require_once $config_file_path;