diff --git a/contracts/deploy/DelegatedCall.sol b/contracts/deploy/DelegatedCall.sol
index 861f751..8612147 100644
--- a/contracts/deploy/DelegatedCall.sol
+++ b/contracts/deploy/DelegatedCall.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.21;
+pragma solidity ^0.4.23;
 
 
 /**
@@ -8,6 +8,10 @@ pragma solidity ^0.4.21;
  *      Important to avoid overwriting wrong storage pointers is that never define storage to this contract
  */
 contract DelegatedCall {
+
+    constructor() internal {
+
+    }
     /**
      * @dev delegates the call of this function
      */
diff --git a/contracts/deploy/Factory.sol b/contracts/deploy/Factory.sol
index 4ba811f..52c0707 100644
--- a/contracts/deploy/Factory.sol
+++ b/contracts/deploy/Factory.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.17;
+pragma solidity ^0.4.23;
 
 import "../common/Controlled.sol";
 
@@ -19,7 +19,7 @@ contract Factory is Controlled {
     uint256 latestUpdate;
     address latestKernel;
 
-    function Factory(address _kernel)
+    constructor(address _kernel)
         public 
     {
         _setKernel(_kernel);
diff --git a/contracts/deploy/Instance.sol b/contracts/deploy/Instance.sol
index 6243711..967bb5f 100644
--- a/contracts/deploy/Instance.sol
+++ b/contracts/deploy/Instance.sol
@@ -10,7 +10,7 @@ import "./DelegatedCall.sol";
  */
 contract Instance is InstanceStorage, DelegatedCall {
 
-    function Instance(address _kernel) public {
+    constructor(address _kernel) public {
         kernel = _kernel;
     }
 
diff --git a/contracts/deploy/InstanceStorage.sol b/contracts/deploy/InstanceStorage.sol
index ba84f64..df766b3 100644
--- a/contracts/deploy/InstanceStorage.sol
+++ b/contracts/deploy/InstanceStorage.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.17;
+pragma solidity ^0.4.23;
 
 
 /**
@@ -12,4 +12,5 @@ contract InstanceStorage {
     // protected zone start (InstanceStorage vars)
     address public kernel;
     // protected zone end
+    constructor() internal { }
 }
\ No newline at end of file
diff --git a/contracts/deploy/UpdatableInstance.sol b/contracts/deploy/UpdatableInstance.sol
index 60f6d0a..9427c5b 100644
--- a/contracts/deploy/UpdatableInstance.sol
+++ b/contracts/deploy/UpdatableInstance.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.17;
+pragma solidity ^0.4.23;
 
 import "./Instance.sol";
 
@@ -12,7 +12,7 @@ contract UpdatableInstance is Instance {
 
     event InstanceUpdated(address oldKernel, address newKernel);
 
-    function UpdatableInstance(address _kernel) 
+    constructor(address _kernel) 
         Instance(_kernel) 
         public
     {