diff --git a/example/natspec_contract.html b/example/natspec_contract.html
index 8d12b4a81..2548495b7 100644
--- a/example/natspec_contract.html
+++ b/example/natspec_contract.html
@@ -3,6 +3,7 @@
 
 <head>
 <script type="text/javascript" src="js/es6-promise/promise.min.js"></script>
+<script type="text/javascript" src="js/bignumber.js/bignumber.min.js"></script>
 <script type="text/javascript" src="../dist/ethereum.js"></script>
 <script type="text/javascript">
 
@@ -44,7 +45,7 @@
 
         // create contract
         web3.eth.transact({code: web3.eth.solidity(source)}).then(function (address) {
-            contract = web3.contract(address, desc);
+            contract = web3.eth.contract(address, desc);
             document.getElementById('call').style.visibility = 'visible';
         });
     }
