diff --git a/tutorial-01/myfirstcontract.sol b/tutorial-01/myfirstcontract.sol
index b921078..a2ae8b4 100644
--- a/tutorial-01/myfirstcontract.sol
+++ b/tutorial-01/myfirstcontract.sol
@@ -1,14 +1,14 @@
-pragma solidity ^0.4.0;
+pragma solidity ^0.5.0;
 
 contract MyFirstContract {
     string private name;
     uint private age;
     
-    function setName(string newName) public {
+    function setName(string memory newName) public {
         name = newName;
     }
     
-    function getName() public view returns (string) {
+    function getName() public view returns (string memory) {
         return name;
     }
     
diff --git a/tutorial-02/myfirstcontract.sol b/tutorial-02/myfirstcontract.sol
index af0d797..f94fce1 100644
--- a/tutorial-02/myfirstcontract.sol
+++ b/tutorial-02/myfirstcontract.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.0;
+pragma solidity ^0.5.0;
 
 interface Regulator {
     function checkValue(uint amount) external returns (bool);
@@ -40,11 +40,11 @@ contract MyFirstContract is Bank(10) {
     string private name;
     uint private age;
     
-    function setName(string newName) public {
+    function setName(string memory newName) public {
         name = newName;
     }
     
-    function getName() public view returns (string) {
+    function getName() public view returns (string memory) {
         return name;
     }
     
diff --git a/tutorial-09/MyToken.sol b/tutorial-09/MyToken.sol
index 0bd4728..635e9d3 100644
--- a/tutorial-09/MyToken.sol
+++ b/tutorial-09/MyToken.sol
@@ -11,19 +11,19 @@ contract MyFirstToken is ERC20 {
     mapping (address => uint) private __balanceOf;
     mapping (address => mapping (address => uint)) private __allowances;
     
-    function MyFirstToken() {
+    constructor() public {
             __balanceOf[msg.sender] = __totalSupply;
     }
     
-    function totalSupply() constant returns (uint _totalSupply) {
+    function totalSupply() public constant returns (uint _totalSupply) {
         _totalSupply = __totalSupply;
     }
     
-    function balanceOf(address _addr) constant returns (uint balance) {
+    function balanceOf(address _addr) public constant returns (uint balance) {
         return __balanceOf[_addr];
     }
     
-    function transfer(address _to, uint _value) returns (bool success) {
+    function transfer(address _to, uint _value) public returns (bool success) {
         if (_value > 0 && _value <= balanceOf(msg.sender)) {
             __balanceOf[msg.sender] -= _value;
             __balanceOf[_to] += _value;
@@ -32,7 +32,7 @@ contract MyFirstToken is ERC20 {
         return false;
     }
     
-    function transferFrom(address _from, address _to, uint _value) returns (bool success) {
+    function transferFrom(address _from, address _to, uint _value) public returns (bool success) {
         if (__allowances[_from][msg.sender] > 0 &&
             _value > 0 &&
             __allowances[_from][msg.sender] >= _value && 
@@ -46,12 +46,12 @@ contract MyFirstToken is ERC20 {
         return false;
     }
     
-    function approve(address _spender, uint _value) returns (bool success) {
+    function approve(address _spender, uint _value) public returns (bool success) {
         __allowances[msg.sender][_spender] = _value;
         return true;
     }
     
-    function allowance(address _owner, address _spender) constant returns (uint remaining) {
+    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
         return __allowances[_owner][_spender];
     }
 }
diff --git a/tutorial-10/ERC20.sol b/tutorial-10/ERC20.sol
index 92c9657..313b5d7 100644
--- a/tutorial-10/ERC20.sol
+++ b/tutorial-10/ERC20.sol
@@ -1,8 +1,8 @@
 pragma solidity ^0.4.0;
 
 interface ERC20 {
-    function transferFrom(address _from, address _to, uint _value) public returns (bool);
-    function approve(address _spender, uint _value) public returns (bool);
-    function allowance(address _owner, address _spender) public constant returns (uint);
+    function transferFrom(address _from, address _to, uint _value) external returns (bool);
+    function approve(address _spender, uint _value) external returns (bool);
+    function allowance(address _owner, address _spender) external constant returns (uint);
     event Approval(address indexed _owner, address indexed _spender, uint _value);
-}
\ No newline at end of file
+}
diff --git a/tutorial-10/ERC223.sol b/tutorial-10/ERC223.sol
index ed72fee..c8b8cf5 100644
--- a/tutorial-10/ERC223.sol
+++ b/tutorial-10/ERC223.sol
@@ -3,4 +3,4 @@ pragma solidity ^0.4.0;
 interface ERC223 {
     function transfer(address _to, uint _value, bytes _data) public returns (bool);
     event Transfer(address indexed from, address indexed to, uint value, bytes indexed data);
-}
\ No newline at end of file
+}
diff --git a/tutorial-10/MyFirstToken.sol b/tutorial-10/MyFirstToken.sol
index c1ae1ca..36321be 100644
--- a/tutorial-10/MyFirstToken.sol
+++ b/tutorial-10/MyFirstToken.sol
@@ -7,7 +7,7 @@ import "browser/ERC223ReceivingContract.sol";
 
 contract MyFirstToken is Token("MFT", "My First Token", 18, 1000), ERC20, ERC223 {
 
-    function MyFirstToken() public {
+    constructor() public {
         _balanceOf[msg.sender] = _totalSupply;
     }
     
@@ -25,7 +25,7 @@ contract MyFirstToken is Token("MFT", "My First Token", 18, 1000), ERC20, ERC223
             !isContract(_to)) {
             _balanceOf[msg.sender] -= _value;
             _balanceOf[_to] += _value;
-            Transfer(msg.sender, _to, _value);
+            emit Transfer(msg.sender, _to, _value);
             return true;
         }
         return false;
@@ -39,13 +39,13 @@ contract MyFirstToken is Token("MFT", "My First Token", 18, 1000), ERC20, ERC223
             _balanceOf[_to] += _value;
             ERC223ReceivingContract _contract = ERC223ReceivingContract(_to);
                 _contract.tokenFallback(msg.sender, _value, _data);
-            Transfer(msg.sender, _to, _value, _data);
+            emit Transfer(msg.sender, _to, _value, _data);
             return true;
         }
         return false;
     }
 
-    function isContract(address _addr) returns (bool) {
+    function isContract(address _addr) public view returns (bool) {
         uint codeSize;
         assembly {
             codeSize := extcodesize(_addr)
@@ -61,7 +61,7 @@ contract MyFirstToken is Token("MFT", "My First Token", 18, 1000), ERC20, ERC223
             _balanceOf[_from] -= _value;
             _balanceOf[_to] += _value;
             _allowances[_from][msg.sender] -= _value;
-            Transfer(_from, _to, _value);
+            emit Transfer(_from, _to, _value);
             return true;
         }
         return false;
@@ -69,11 +69,11 @@ contract MyFirstToken is Token("MFT", "My First Token", 18, 1000), ERC20, ERC223
     
     function approve(address _spender, uint _value) public returns (bool) {
         _allowances[msg.sender][_spender] = _value;
-        Approval(msg.sender, _spender, _value);
+        emit Approval(msg.sender, _spender, _value);
         return true;
     }
     
     function allowance(address _owner, address _spender) public constant returns (uint) {
         return _allowances[_owner][_spender];
     }
-}
\ No newline at end of file
+}
diff --git a/tutorial-10/Token.sol b/tutorial-10/Token.sol
index b2670bf..13a2024 100644
--- a/tutorial-10/Token.sol
+++ b/tutorial-10/Token.sol
@@ -8,7 +8,7 @@ contract Token {
     mapping (address => uint) internal _balanceOf;
     mapping (address => mapping (address => uint)) internal _allowances;
     
-    function Token(string symbol, string name, uint8 decimals, uint totalSupply) public {
+    constructor(string symbol, string name, uint8 decimals, uint totalSupply) public {
         _symbol = symbol;
         _name = name;
         _decimals = decimals;
@@ -34,4 +34,4 @@ contract Token {
     function balanceOf(address _addr) public constant returns (uint);
     function transfer(address _to, uint _value) public returns (bool);
     event Transfer(address indexed _from, address indexed _to, uint _value);
-}
\ No newline at end of file
+}
diff --git a/tutorial-14/EtherTransfer.sol b/tutorial-14/EtherTransfer.sol
index a61a92a..1d50789 100644
--- a/tutorial-14/EtherTransfer.sol
+++ b/tutorial-14/EtherTransfer.sol
@@ -1,7 +1,7 @@
-pragma solidity ^0.4.0;
+pragma solidity ^0.5.0;
 
 contract EtherTransferTo {
-    function () public payable {
+    function () external payable {
     }
     
     function getBalance() public returns (uint) {
@@ -13,7 +13,7 @@ contract EtherTransferFrom {
     
     EtherTransferTo private _instance;
     
-    function EtherTransferFrom() public {
+    constructor() public {
         // _instance = EtherTransferTo(address(this));
         _instance = new EtherTransferTo();
     }
@@ -27,7 +27,7 @@ contract EtherTransferFrom {
         return _instance.getBalance();
     }
     
-    function () public payable {
+    function () external payable {
         //msg.sender.send(msg.value);
         address(_instance).send(msg.value);
     }
diff --git a/tutorial-15/ExternalContract.sol b/tutorial-15/ExternalContract.sol
index 346c076..17e7328 100644
--- a/tutorial-15/ExternalContract.sol
+++ b/tutorial-15/ExternalContract.sol
@@ -1,11 +1,11 @@
-pragma solidity ^0.4.0;
+pragma solidity ^0.5.0;
 
 contract ExternalContract {
-    function externalCall(string x) external returns (uint) {
+    function externalCall(string calldata x) external returns (uint) {
         return 123;
     }
     
-    function publicCall(string x) public returns (uint) {
+    function publicCall(string memory x) public returns (uint) {
         return 123;
     }
-}
\ No newline at end of file
+}
diff --git a/tutorial-16/AlarmTrigger.sol b/tutorial-16/AlarmTrigger.sol
index 04a13d7..b474f57 100644
--- a/tutorial-16/AlarmTrigger.sol
+++ b/tutorial-16/AlarmTrigger.sol
@@ -1,7 +1,7 @@
-pragma solidity ^0.4.0;
+pragma solidity ^0.5.0;
 
 interface AlarmWakeUp {
-    function callback(bytes _data) public;
+    function callback(bytes calldata _data) external;
 }
 
 contract AlarmService {
@@ -16,7 +16,7 @@ contract AlarmService {
     function set(uint _time) 
         public 
         returns (bool) {
-        TimeEvent _timeEvent;
+        TimeEvent memory _timeEvent;
         _timeEvent.addr = msg.sender;
         _timeEvent.data = msg.data;
         _events[_time].push(_timeEvent);
@@ -24,7 +24,7 @@ contract AlarmService {
     
     function call(uint _time) 
         public {
-        TimeEvent[] timeEvents = _events[_time];
+        TimeEvent[] memory timeEvents = _events[_time];
         for(uint i = 0; i < timeEvents.length; i++) {
             AlarmWakeUp(timeEvents[i].addr).callback(timeEvents[i].data);
         }
@@ -35,11 +35,11 @@ contract AlarmTrigger is AlarmWakeUp {
     
     AlarmService private _alarmService;
     
-    function AlarmTrigger() {
+    constructor() public {
         _alarmService = new AlarmService();
     }
     
-    function callback(bytes _data) 
+    function callback(bytes memory _data) 
         public {
         // Do something
     }
diff --git a/tutorial-16/TimeBased.sol b/tutorial-16/TimeBased.sol
index 27f22c0..c921a61 100644
--- a/tutorial-16/TimeBased.sol
+++ b/tutorial-16/TimeBased.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.4.0;
+pragma solidity ^0.5.0;
 
 contract TimeBased {
     
diff --git a/tutorial-24/MultiSigWallet.sol b/tutorial-24/MultiSigWallet.sol
index c1375f8..71d30f3 100644
--- a/tutorial-24/MultiSigWallet.sol
+++ b/tutorial-24/MultiSigWallet.sol
@@ -19,7 +19,7 @@ contract MultiSigWallet {
     event WithdrawFunds(address to, uint amount);
     event TransferFunds(address from, address to, uint amount);
     
-    function MultiSigWallet()
+    constructor()
         public {
         _owner = msg.sender;
     }
@@ -39,7 +39,7 @@ contract MultiSigWallet {
     function ()
         public
         payable {
-        DepositFunds(msg.sender, msg.value);
+        emit DepositFunds(msg.sender, msg.value);
     }
     
     function withdraw(uint amount)
@@ -47,15 +47,15 @@ contract MultiSigWallet {
         public {
         require(address(this).balance >= amount);
         msg.sender.transfer(amount);
-        WithdrawFunds(msg.sender, amount);
+        emit WithdrawFunds(msg.sender, amount);
     }
     
     function transferTo(address to, uint amount) 
         validOwner
         public {
         require(address(this).balance >= amount);
-        msg.sender.transfer(amount);
-        TransferFunds(msg.sender, to, amount);
+        to.transfer(amount);
+        emit TransferFunds(msg.sender, to, amount);
     }
         
-}
\ No newline at end of file
+}