diff --git a/contracts/deploy/Factory.sol b/contracts/deploy/Factory.sol
index f63bf71..2408a58 100644
--- a/contracts/deploy/Factory.sol
+++ b/contracts/deploy/Factory.sol
@@ -4,54 +4,87 @@ import "../common/Controlled.sol";
 
 contract Factory is Controlled {
 
-    event NewKernel(address newKernel, bytes infohash);
+    event NewKernel(address newKernel, bytes32 codeHash);
 
     struct Version {
         uint256 blockNumber;
         uint256 timestamp;
         address kernel;
-        bytes infohash;
+        bytes32 codeHash;
     }
+
     mapping (address => uint256) versionMap;
 
     Version[] versionLog;
     uint256 latestUpdate;
     address latestKernel;
 
-    function Factory(address _kernel, bytes _infohash)
+    function Factory(address _kernel)
         public 
     {
-        _setKernel(_kernel, _infohash);
+        _setKernel(_kernel);
     }
 
-    function setKernel(address _kernel, bytes _infohash)
+    function setKernel(address _kernel)
         external 
         onlyController
     {
-        _setKernel(_kernel, _infohash);
+        _setKernel(_kernel);
     }
 
-    function getVersion(uint256 index) public view
-        returns(uint256 blockNumber,
-                uint256 timestamp,
-                address kernel,
-                bytes infohash)
+    function getVersion(uint256 index)
+        public
+        view
+        returns(
+            uint256 blockNumber,
+            uint256 timestamp,
+            address kernel,
+            bytes32 codeHash
+        )
     {
-        return (versionLog[index].blockNumber, 
-                versionLog[index].timestamp, 
-                versionLog[index].kernel, 
-                versionLog[index].infohash);
+        return (
+            versionLog[index].blockNumber, 
+            versionLog[index].timestamp, 
+            versionLog[index].kernel, 
+            versionLog[index].codeHash
+        );
     }
 
-    function _setKernel(address _kernel, bytes _infohash) 
+    function getCodeHash(address _addr) 
+        public 
+        view 
+        returns (bytes32 codeHash) 
+    {
+        bytes memory o_code;
+        uint size;
+        assembly {
+            // retrieve the size of the code, this needs assembly
+            size := extcodesize(_addr)
+        }
+        require (size > 0);
+        assembly {
+            // allocate output byte array - this could also be done without assembly
+            // by using o_code = new bytes(size)
+            o_code := mload(0x40)
+            // new "memory end" including padding
+            mstore(0x40, add(o_code, and(add(add(size, 0x20), 0x1f), bnot(0x1f))))
+            // store length in memory
+            mstore(o_code, size)
+            // actually retrieve the code, this needs assembly
+            extcodecopy(_addr, add(o_code, 0x20), 0, size)
+        }
+        codeHash = keccak256(o_code);
+    }
+
+    function _setKernel(address _kernel) 
         internal
     {
         require(_kernel != latestKernel);
+        bytes32 _codeHash = getCodeHash(_kernel);
         versionMap[_kernel] = versionLog.length;
-        versionLog.push(Version({blockNumber: block.number, timestamp: block.timestamp, kernel: _kernel, infohash: _infohash}));
+        versionLog.push(Version({blockNumber: block.number, timestamp: block.timestamp, kernel: _kernel, codeHash: _codeHash}));
         latestUpdate = block.timestamp;
         latestKernel = _kernel;
-        NewKernel(_kernel, _infohash);
+        NewKernel(_kernel, _codeHash);
     }
-
 }
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