diff --git a/unittests/json_3.chai b/unittests/json_3.chai
index 11ce7dcb..1308c492 100644
--- a/unittests/json_3.chai
+++ b/unittests/json_3.chai
@@ -1,2 +1,3 @@
 assert_equal(from_json("100"), 100)
 assert_equal(from_json("-100"), -100)
+assert_equal(to_json(4294967295), "4294967295")