diff --git a/decimal.d.ts b/decimal.d.ts
index 0fbc7b2..e402317 100644
--- a/decimal.d.ts
+++ b/decimal.d.ts
@@ -57,13 +57,13 @@ export declare class Decimal {
   readonly e: number;
   readonly s: number;
 
-  constructor(n: Decimal.Value);
+  constructor(n?: Decimal.Value);
 
   absoluteValue(): Decimal;
   abs(): Decimal;
 
   ceil(): Decimal;
-  
+
   clampedTo(min: Decimal.Value, max: Decimal.Value): Decimal;
   clamp(min: Decimal.Value, max: Decimal.Value): Decimal;
 
diff --git a/decimal.global.d.ts b/decimal.global.d.ts
index 6b28256..49d0f50 100644
--- a/decimal.global.d.ts
+++ b/decimal.global.d.ts
@@ -78,13 +78,13 @@ export declare class Decimal {
   readonly e: number;
   readonly s: number;
 
-  constructor(n: DecimalValue);
+  constructor(n?: DecimalValue);
 
   absoluteValue(): Decimal;
   abs(): Decimal;
 
   ceil(): Decimal;
-  
+
   clampedTo(min: Decimal.Value, max: Decimal.Value): Decimal;
   clamp(min: Decimal.Value, max: Decimal.Value): Decimal;
 
diff --git a/decimal.js b/decimal.js
index aa6526a..f4eb329 100644
--- a/decimal.js
+++ b/decimal.js
@@ -4283,6 +4283,7 @@
      *
      */
     function Decimal(v) {
+      if (typeof v === 'undefined') v = 0
       var e, i, t,
         x = this;
 
diff --git a/decimal.mjs b/decimal.mjs
index 909300c..9e8ec16 100644
--- a/decimal.mjs
+++ b/decimal.mjs
@@ -4279,6 +4279,7 @@ function clone(obj) {
    *
    */
   function Decimal(v) {
+    if (typeof v === 'undefined') v = 0
     var e, i, t,
       x = this;
 
diff --git a/test/modules/Decimal.js b/test/modules/Decimal.js
index 24c5897..0865574 100644
--- a/test/modules/Decimal.js
+++ b/test/modules/Decimal.js
@@ -278,7 +278,6 @@ T('Decimal', function () {
   t('123.456789', '123.456789');
   t('123.456789', '+123.456789');
 
-  tx(function () {new Decimal(void 0)}, "void 0");
   tx(function () {new Decimal('undefined')}, "'undefined'");
   tx(function () {new Decimal(null)}, "null");
   tx(function () {new Decimal('null')}, "'null'");
diff --git a/test/modules/intPow.js b/test/modules/intPow.js
index b772fea..57f939b 100644
--- a/test/modules/intPow.js
+++ b/test/modules/intPow.js
@@ -540,7 +540,6 @@ T('integer pow', function () {
   t('1.494189395849269188211255039709933309086424259778445906419464942576097148044216376789735318980392750336285644804638743600807550074206128272345650029255016954321611264002141919840462369550905098763723254901675135787504979910497931539962354019230845564318816091666473025536e+126', '-32698949771.110178432792', 12);
   t('1.1504940871276742926708823617505372960241390892442547940194260102743306128298973371802547471453755938653944600792141533514422490556963535378521856840746722206160260148176604222079226186281680715577736316488196108040509176925372372483300649927835887344415603493563915019264675154039059770309142781930141352329958156926976e+15', '-8.7358521345995835476', 16);
 
-  tx(function () {new Decimal('12.345').pow(void 0)}, ".pow(void 0)");
   tx(function () {new Decimal('12.345').pow(null)}, ".pow(null)");
   tx(function () {new Decimal('12.345').pow(true)}, ".pow(true)");
   tx(function () {new Decimal('12.345').pow(false)}, ".pow(false)");