4 files changed, 39 insertions, 7 deletions
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol b/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol
index ea82e9d64..0735ec40a 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol
@@ -18,16 +18,16 @@
 
 pragma solidity 0.4.24;
 
-import "../protocol/Exchange/Exchange.sol";
-import { WETH9 as EtherToken } from "../tokens/WETH9/WETH9.sol";
+import "../protocol/Exchange/interfaces/IExchange.sol";
+import "../tokens/EtherToken/IEtherToken.sol";
 import "../tokens/ERC20Token/IERC20Token.sol";
 
 
 contract MixinConstants {
 
     // solhint-disable var-name-mixedcase
-    Exchange internal EXCHANGE;
-    EtherToken internal ETHER_TOKEN;
+    IExchange internal EXCHANGE;
+    IEtherToken internal ETHER_TOKEN;
     IERC20Token internal ZRX_TOKEN;
     bytes internal ZRX_ASSET_DATA;
     bytes internal WETH_ASSET_DATA;
@@ -42,8 +42,8 @@ contract MixinConstants {
     )
         public
     {
-        EXCHANGE = Exchange(_exchange);
-        ETHER_TOKEN = EtherToken(_etherToken);
+        EXCHANGE = IExchange(_exchange);
+        ETHER_TOKEN = IEtherToken(_etherToken);
         ZRX_TOKEN = IERC20Token(_zrxToken);
         ZRX_ASSET_DATA = _zrxAssetData;
         WETH_ASSET_DATA = _wethAssetData;
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol b/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
index 12392be79..c8069aa8c 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
@@ -18,7 +18,6 @@
 
 pragma solidity 0.4.24;
 
-import { WETH9 as EtherToken } from "../tokens/WETH9/WETH9.sol";
 import "../protocol/Exchange/libs/LibMath.sol";
 import "./MixinConstants.sol";
 
diff --git a/packages/contracts/src/2.0.0/tokens/EtherToken/IEtherToken.sol b/packages/contracts/src/2.0.0/tokens/EtherToken/IEtherToken.sol
new file mode 100644
index 000000000..9e2e68766
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/EtherToken/IEtherToken.sol
@@ -0,0 +1,33 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+import "../ERC20Token/IERC20Token.sol";
+
+
+contract IEtherToken is
+    IERC20Token
+{
+    function deposit()
+        public
+        payable;
+    
+    function withdraw(uint256 amount)
+        public;
+}
diff --git a/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol b/packages/contracts/src/2.0.0/tokens/EtherToken/WETH9.sol
index 1fdb04de5..1fdb04de5 100644
--- a/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol
+++ b/packages/contracts/src/2.0.0/tokens/EtherToken/WETH9.sol