diff --git a/jsonld-tests.php b/jsonld-tests.php
index 1eafe26..7c889b9 100644
--- a/jsonld-tests.php
+++ b/jsonld-tests.php
@@ -389,7 +389,8 @@ class TestRunner {
         // read test input files
         $type = $test->{'@type'};
         $options = array(
-          'base' => 'http://json-ld.org/test-suite/tests/' . $test->input);
+          'base' => 'http://json-ld.org/test-suite/tests/' . $test->input,
+          'useNativeTypes' => true);
 
         $pass = false;
         try {