3 files changed, 8 insertions, 11 deletions
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 99d3d9256..24551dd93 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -38,6 +38,7 @@
         "@0xproject/types": "^0.7.0",
         "@0xproject/typescript-typings": "^0.3.2",
         "@types/node": "^8.0.53",
+        "ethereumjs-util": "^5.1.1",
         "bignumber.js": "~4.1.0",
         "ethers": "^3.0.15",
         "js-sha3": "^0.7.0",
diff --git a/packages/utils/src/abi_decoder.ts b/packages/utils/src/abi_decoder.ts
index c78bfa343..d2d8364ca 100644
--- a/packages/utils/src/abi_decoder.ts
+++ b/packages/utils/src/abi_decoder.ts
@@ -12,21 +12,12 @@ import {
 import * as ethers from 'ethers';
 import * as _ from 'lodash';
 
+import { addressUtils } from './address_utils';
 import { BigNumber } from './configured_bignumber';
 
 export class AbiDecoder {
     private _savedABIs: AbiDefinition[] = [];
     private _methodIds: { [signatureHash: string]: EventAbi } = {};
-    private static _padZeros(address: string): string {
-        let formatted = address;
-        if (_.startsWith(formatted, '0x')) {
-            formatted = formatted.slice(2);
-        }
-
-        const addressLength = 40;
-        formatted = _.padStart(formatted, addressLength, '0');
-        return `0x${formatted}`;
-    }
     constructor(abiArrays: AbiDefinition[][]) {
         _.forEach(abiArrays, this.addABI.bind(this));
     }
@@ -56,7 +47,7 @@ export class AbiDecoder {
             }
             if (param.type === SolidityTypes.Address) {
                 const baseHex = 16;
-                value = AbiDecoder._padZeros(new BigNumber(value).toString(baseHex));
+                value = addressUtils.padZeros(new BigNumber(value).toString(baseHex));
             } else if (param.type === SolidityTypes.Uint256 || param.type === SolidityTypes.Uint) {
                 value = new BigNumber(value);
             } else if (param.type === SolidityTypes.Uint8) {
diff --git a/packages/utils/src/address_utils.ts b/packages/utils/src/address_utils.ts
index e25bde249..cc43bd477 100644
--- a/packages/utils/src/address_utils.ts
+++ b/packages/utils/src/address_utils.ts
@@ -1,4 +1,6 @@
+import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
 import * as jsSHA3 from 'js-sha3';
+import * as _ from 'lodash';
 
 const BASIC_ADDRESS_REGEX = /^(0x)?[0-9a-f]{40}$/i;
 const SAME_CASE_ADDRESS_REGEX = /^(0x)?([0-9a-f]{40}|[0-9A-F]{40})$/;
@@ -38,4 +40,7 @@ export const addressUtils = {
             return isValidChecksummedAddress;
         }
     },
+    padZeros(address: string): string {
+        return addHexPrefix(_.padStart(stripHexPrefix(address), 40, '0'));
+    },
 };