diff --git a/contracts/DelegatedCall.sol b/contracts/DelegatedCall.sol
index 18b2851..6ae754c 100644
--- a/contracts/DelegatedCall.sol
+++ b/contracts/DelegatedCall.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.12;
+pragma solidity ^0.4.18;
 
 /**
  * @title DelegatedCall
diff --git a/contracts/ERC20.sol b/contracts/ERC20.sol
index e82eabb..fb47128 100644
--- a/contracts/ERC20.sol
+++ b/contracts/ERC20.sol
@@ -1,12 +1,12 @@
-pragma solidity ^0.4.15;
+pragma solidity ^0.4.18;
 
 contract ERC20 {
     uint256 public totalSupply;
-    function balanceOf(address who) constant returns (uint256);
-    function allowance(address owner, address spender) constant returns (uint256);
-    function transfer(address to, uint256 value) returns (bool ok);
-    function transferFrom(address from, address to, uint256 value) returns (bool ok);
-    function approve(address spender, uint256 value) returns (bool ok);
+    function balanceOf(address who) public constant returns (uint256);
+    function allowance(address owner, address spender) public constant returns (uint256);
+    function transfer(address to, uint256 value) public returns (bool ok);
+    function transferFrom(address from, address to, uint256 value) public returns (bool ok);
+    function approve(address spender, uint256 value) public returns (bool ok);
     event Transfer(address indexed from, address indexed to, uint256 value);
     event Approval(address indexed owner, address indexed spender, uint256 value);
 }
\ No newline at end of file
diff --git a/contracts/MultiSigFactory.sol b/contracts/MultiSigFactory.sol
index 99e80ae..30a5ac3 100644
--- a/contracts/MultiSigFactory.sol
+++ b/contracts/MultiSigFactory.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.15;
+pragma solidity ^0.4.18;
 
 import "./MultiSigStub.sol";
 
diff --git a/contracts/MultiSigStub.sol b/contracts/MultiSigStub.sol
index 6c7451b..709bda0 100644
--- a/contracts/MultiSigStub.sol
+++ b/contracts/MultiSigStub.sol
@@ -1,9 +1,10 @@
-pragma solidity ^0.4.15;
+pragma solidity ^0.4.18;
 
 import "./DelegatedCall.sol";
 
 /**
  * @title MultiSigStub  
+ * @author Ricardo Guilherme Schmidt (Status Research & Development GmbH) 
  * Contract that delegates calls to a library to build a full MultiSigWallet that is cheap to create. 
  */
 contract MultiSigStub is DelegatedCall {