diff --git a/util/build.js b/util/build.js
index 14855bbe8..344a85e89 100755
--- a/util/build.js
+++ b/util/build.js
@@ -42,6 +42,7 @@ var createBundle = function(opts) {
   b.require('./copay', {
     expose: 'copay'
   });
+  b.external('bitcore');
   b.require('./js/models/core/WalletFactory');
   b.require('./js/models/core/Wallet');
   b.require('./js/models/core/Wallet', {