diff --git a/lib/unit.js b/lib/unit.js
index 983c818..f2ca33c 100644
--- a/lib/unit.js
+++ b/lib/unit.js
@@ -23,6 +23,10 @@
  */
 
 function Unit(amount, code) {
+  if (!(this instanceof Unit)) {
+    return new Unit(amount, code);
+  }
+
   this._value = this._from(amount, code);
 
   var self = this;