2 files changed, 2 insertions, 4 deletions
diff --git a/packages/contracts/src/utils/asset_proxy_utils.ts b/packages/contracts/src/utils/asset_proxy_utils.ts
index 63de7252d..529d31cb9 100644
--- a/packages/contracts/src/utils/asset_proxy_utils.ts
+++ b/packages/contracts/src/utils/asset_proxy_utils.ts
@@ -5,9 +5,7 @@ import ethUtil = require('ethereumjs-util');
 import { AssetProxyId } from './types';
 
 export function encodeAssetProxyId(assetProxyId: AssetProxyId): Buffer {
-    const formattedAssetProxyId = new BN(assetProxyId);
-    const encodedAssetProxyId = ethUtil.toUnsigned(formattedAssetProxyId);
-    return encodedAssetProxyId;
+    return ethUtil.toBuffer(assetProxyId);
 }
 
 export function encodeAddress(address: string): Buffer {
diff --git a/packages/contracts/src/utils/crypto.ts b/packages/contracts/src/utils/crypto.ts
index 5bc678cdf..222cb7cca 100644
--- a/packages/contracts/src/utils/crypto.ts
+++ b/packages/contracts/src/utils/crypto.ts
@@ -31,7 +31,7 @@ export const crypto = {
                 argTypes.push('address');
             } else if (_.isString(arg)) {
                 argTypes.push('string');
-            } else if (arg instanceof Buffer) {
+            } else if (_.isBuffer(arg)) {
                 argTypes.push('bytes');
             } else if (_.isBoolean(arg)) {
                 argTypes.push('bool');