diff --git a/bignumber.js b/bignumber.js
index 7845cfb..1b91a9c 100644
--- a/bignumber.js
+++ b/bignumber.js
@@ -2715,7 +2715,7 @@
 
 
     BigNumber = constructorFactory();
-    BigNumber.default = BigNumber.BigNumber = BigNumber;
+    BigNumber['default'] = BigNumber.BigNumber = BigNumber;
 
 
     // AMD.