diff --git a/tests/test.rs b/tests/test.rs
index 1d7e8cb..e42edff 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -26,4 +26,5 @@ test! {
     test_u128_0(0u128, "0")
     test_u128_max(u128::max_value(), "340282366920938463463374607431768211455")
     test_i128_min(i128::min_value(), "-170141183460469231731687303715884105728")
+    test_i128_max(i128::MAX, "170141183460469231731687303715884105727")
 }