diff --git a/tests/phpunit/Checker/Check_Categories_Tests.php b/tests/phpunit/Checker/Check_Categories_Tests.php
index 7399a80e6..a6d26035b 100644
--- a/tests/phpunit/Checker/Check_Categories_Tests.php
+++ b/tests/phpunit/Checker/Check_Categories_Tests.php
@@ -44,8 +44,7 @@ public function test_filter_checks_by_categories( array $categories, array $all_
 			$this->repository->register_check( $check[0], $check[1] );
 		}
 
-		$checks = $this->repository->get_checks()
-			->to_map();
+		$checks = $this->repository->get_checks();
 
 		$check_categories = new Check_Categories();
 		$filtered_checks  = $check_categories->filter_checks_by_categories( $checks, $categories );