diff --git a/contracts/Crowdsale.sol b/contracts/Crowdsale.sol
index 5d15f2b7..ecec53e5 100644
--- a/contracts/Crowdsale.sol
+++ b/contracts/Crowdsale.sol
@@ -119,11 +119,19 @@ contract Crowdsale is CrowdsaleBase {
    * Invest to tokens, recognize the payer.
    *
    */
-  function buyWithCustomerId(uint128 customerId, bytes1 checksum) public payable {
+  function buyWithCustomerIdWithChecksum(uint128 customerId, bytes1 checksum) public payable {
+    // see customerid.py
     if (bytes1(sha3(customerId)) != checksum) throw;
     investWithCustomerId(msg.sender, customerId);
   }
 
+  /**
+   * Legacy API signature.
+   */
+  function buyWithCustomerId(uint128 customerId) public payable {
+    investWithCustomerId(msg.sender, customerId);
+  }
+
   /**
    * The basic entry point to participate the crowdsale process.
    *
diff --git a/contracts/PaymentForwarder.sol b/contracts/PaymentForwarder.sol
index 678a173a..2a804462 100644
--- a/contracts/PaymentForwarder.sol
+++ b/contracts/PaymentForwarder.sol
@@ -72,6 +72,7 @@ contract PaymentForwarder is Haltable {
    *
    */
    function pay(uint128 customerId, address benefactor, bytes1 checksum) public stopInEmergency payable {
+    // see customerid.py
      if (bytes1(sha3(customerId, benefactor)) != checksum) throw;
      payWithoutChecksum(customerId, benefactor);
    }
@@ -82,9 +83,17 @@ contract PaymentForwarder is Haltable {
    * @param customerId Identifier in the central database, UUID v4
    *
    */
-  function payForMyself(uint128 customerId, bytes1 checksum) public payable {
+  function payForMyselfWithChecksum(uint128 customerId, bytes1 checksum) public payable {
+    // see customerid.py
     if (bytes1(sha3(customerId)) != checksum) throw;
     payWithoutChecksum(customerId, msg.sender);
   }
 
+  /**
+   * Legacy API signature.
+   */
+  function payForMyself(uint128 customerId) public payable {
+    payWithoutChecksum(customerId, msg.sender);
+  }
+
 }
diff --git a/ico/tests/contracts/test_forwarder.py b/ico/tests/contracts/test_forwarder.py
index 3b625acf..12be5ffe 100644
--- a/ico/tests/contracts/test_forwarder.py
+++ b/ico/tests/contracts/test_forwarder.py
@@ -8,6 +8,7 @@
 from sha3 import keccak_256
 from rlp.utils import decode_hex
 
+
 @pytest.fixture
 def payment_forwarder(chain, team_multisig):
     args = [team_multisig, team_multisig]
@@ -93,7 +94,7 @@ def test_pay_for_myself(web3, payment_forwarder, team_multisig, customer):
     team_multisig_begin = web3.eth.getBalance(team_multisig)
 
     checksumbyte = keccak_256(decode_hex(format(customer_id, 'x').zfill(32))).digest()[:1]
-    payment_forwarder.transact({"value": value, "from": customer}).payForMyself(customer_id, checksumbyte)
+    payment_forwarder.transact({"value": value, "from": customer}).payForMyselfWithChecksum(customer_id, checksumbyte)
     team_multisig_end = web3.eth.getBalance(team_multisig)
 
     assert team_multisig_end - team_multisig_begin > 0
diff --git a/ico/tests/contracts/test_require_customer_id.py b/ico/tests/contracts/test_require_customer_id.py
index 95a5a6ff..3dfa23e0 100644
--- a/ico/tests/contracts/test_require_customer_id.py
+++ b/ico/tests/contracts/test_require_customer_id.py
@@ -45,7 +45,7 @@ def test_participate_with_customer_id(chain, crowdsale, customer, customer_id, t
     wei_value = to_wei(1, "ether")
     assert crowdsale.call().getState() == CrowdsaleState.Funding
     checksumbyte = keccak_256(decode_hex(format(customer_id, 'x').zfill(32))).digest()[:1]
-    crowdsale.transact({"from": customer, "value": wei_value}).buyWithCustomerId(customer_id, checksumbyte)
+    crowdsale.transact({"from": customer, "value": wei_value}).buyWithCustomerIdWithChecksum(customer_id, checksumbyte)
 
     # We got credited
     assert token.call().balanceOf(customer) > 0