diff --git a/Registry.sol b/Registry.sol
index ccc1bb6..2c7f44c 100644
--- a/Registry.sol
+++ b/Registry.sol
@@ -12,4 +12,6 @@ interface Registry {
 	function configSumOf(bytes32 _chain) external view returns (bytes32);
 	function set (bytes32 _identifier, address _address, bytes32 _chainDescriptor, bytes32 _chainConfig) external returns (bool);
 	function seal() external returns (bool);
+	// TODO: extend RegistryClient, but flatten files
+	function addressOf(bytes32) external view returns (address);
 }