diff --git a/python/eth_contract_registry/data/Registry.bin b/python/eth_contract_registry/data/Registry.bin
index 626b8d3..efb0547 100644
--- a/python/eth_contract_registry/data/Registry.bin
+++ b/python/eth_contract_registry/data/Registry.bin
@@ -1 +1 @@
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\ No newline at end of file
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\ No newline at end of file
diff --git a/python/eth_contract_registry/data/Registry.json b/python/eth_contract_registry/data/Registry.json
index 54d1a9e..14a98df 100644
--- a/python/eth_contract_registry/data/Registry.json
+++ b/python/eth_contract_registry/data/Registry.json
@@ -1 +1 @@
-[{"inputs":[{"internalType":"bytes32[]","name":"_identifiers","type":"bytes32[]"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[{"internalType":"bytes32","name":"_identifier","type":"bytes32"}],"name":"addressOf","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"_identifier","type":"bytes32"},{"internalType":"bytes32","name":"_reference","type":"bytes32"}],"name":"bind","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"identifiers","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"_identifier","type":"bytes32"},{"internalType":"address","name":"_address","type":"address"}],"name":"set","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
+[{"inputs":[{"internalType":"bytes32[]","name":"_identifiers","type":"bytes32[]"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_previousOwner","type":"address"},{"indexed":true,"internalType":"address","name":"_newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"inputs":[{"internalType":"bytes32","name":"_identifier","type":"bytes32"}],"name":"addressOf","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"_identifier","type":"bytes32"},{"internalType":"bytes32","name":"_reference","type":"bytes32"}],"name":"bind","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"identifiers","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"_identifier","type":"bytes32"},{"internalType":"address","name":"_address","type":"address"}],"name":"set","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
diff --git a/solidity/Registry.sol b/solidity/Registry.sol
index 4263bdf..d7ff83e 100644
--- a/solidity/Registry.sol
+++ b/solidity/Registry.sol
@@ -7,13 +7,17 @@ pragma solidity >0.6.11;
 
 
 contract CICRegistry {
-	// Implements EIP 173
+	// Implements ERC173
 	address public owner;
 
+	// Implements RegistryClient
 	bytes32[] public identifiers;
 	mapping (bytes32 => address) entries;		// contractidentifier -> address
 	mapping (bytes32 => bytes32[]) entryBindings;	// contractidentifier -> chainidentifier
 
+	// Implements ERC173
+	event OwnershipTransferred(address indexed _previousOwner, address indexed _newOwner);
+
 	constructor(bytes32[] memory _identifiers) {
 		owner = msg.sender;
 		for (uint i = 0; i < _identifiers.length; i++) {
@@ -21,6 +25,7 @@ contract CICRegistry {
 		}
 	}
 
+	// Implements Registry
 	function set(bytes32 _identifier, address _address) public returns (bool) {
 		require(msg.sender == owner);
 		require(entries[_identifier] == address(0));
@@ -38,6 +43,7 @@ contract CICRegistry {
 		return true;
 	}
 
+	// Implements Registry
 	function bind(bytes32 _identifier, bytes32 _reference) public returns (bool) {
 		require(msg.sender == owner);
 		require(entries[_identifier] != address(0));
@@ -48,27 +54,32 @@ contract CICRegistry {
 
 	// Implements EIP 173
 	function transferOwnership(address _newOwner) public returns (bool) {
+		address _oldOwner;
+
 		require(msg.sender == owner);
+		_oldOwner = owner;
 		owner = _newOwner;
+		emit OwnershipTransferred(_oldOwner, _newOwner);
 		return true;
 	}
 
-	// Implements Registry
+	// Implements RegistryClient
 	function addressOf(bytes32 _identifier) public view returns (address) {
 		return entries[_identifier];
 	}
 
+	// Implements ERC165
 	function supportsInterface(bytes4 _sum) public pure returns (bool) {
-		if (_sum == 0xffeb6416) { // Registry
+		if (_sum == 0xd719b0cc) { // Registry
 			return true;
 		}
-		if (_sum == 0xbb34534c) { // RegistryClient
+		if (_sum == 0x93c68796) { // RegistryClient
 			return true;
 		}
-		if (_sum == 0x01ffc9a7) { // EIP165
+		if (_sum == 0x01ffc9a7) { // ERC165
 			return true;
 		}
-		if (_sum == 0x9493f8b2) { // EIP173
+		if (_sum == 0x9493f8b2) { // ERC173
 			return true;
 		}
 		return false;