diff --git a/test/modules/plus.js b/test/modules/plus.js
index 4472c50..aa7e100 100644
--- a/test/modules/plus.js
+++ b/test/modules/plus.js
@@ -1040,4 +1040,10 @@ T('plus', function () {
   t('-3.60348795228017780049569753533186294E+499', '8.80786821E+82223318', '8.80786821e+82223318', 28, 0);
   t('-9.8967145096522848735804634E+98677519', '-8.39861E+5784323495519916', '-8.39e+5784323495519916', 3, 1);
   t('-5.54480709948277E-718373854', '-7.119627881088288640389987E-896127305535', '-5.54480709948277e-718373854', 56, 6);
+
+  const a = new Decimal('-13.77');
+  const b = new Decimal('1.5612555115940468637');
+  const c = new Decimal('5');
+
+  T.assertEqual(a.plus(b).plus(c), a.plus(b.plus(c)));
 });