diff --git a/tests/test_codewars/test_chinese_numeral_encoder.py b/tests/test_codewars/test_chinese_numeral_encoder.py
index dd35607..b80cd8e 100644
--- a/tests/test_codewars/test_chinese_numeral_encoder.py
+++ b/tests/test_codewars/test_chinese_numeral_encoder.py
@@ -12,3 +12,4 @@ def test_to_chinese():
     assert to_chinese_numeral(10000) == "一万"
     assert to_chinese_numeral(10006) == "一万零六"
     assert to_chinese_numeral(10306.005) == "一万零三百零六点零零五"
+    assert to_chinese_numeral(-10.000001) == "负十点零零零零零一"