diff --git a/tests/phpunit/includes/bootstrap.php b/tests/phpunit/includes/bootstrap.php
index 9db419f18a379..4e369c1f45363 100644
--- a/tests/phpunit/includes/bootstrap.php
+++ b/tests/phpunit/includes/bootstrap.php
@@ -216,7 +216,7 @@
 define( 'DIR_TESTROOT', realpath( dirname( __DIR__ ) ) );
 define( 'IMPORTER_PLUGIN_FOR_TESTS', DIR_TESTDATA . '/plugins/wordpress-importer/wordpress-importer.php' );
 
-if ( ! file_exists( IMPORTER_PLUGIN_FOR_TESTS ) ) {
+if ( defined( 'WP_RUN_CORE_TESTS' ) && WP_RUN_CORE_TESTS && ! file_exists( IMPORTER_PLUGIN_FOR_TESTS ) ) {
 	echo 'The test suite requires the WordPress Importer plugin to be available in the `/data/plugins/` directory.'
 		. ' See: https://make.wordpress.org/core/handbook/contribute/git/#unit-tests' . PHP_EOL,
 	exit( 1 );