From 1b37c21da58f6379cfe09c0140cf56d67b19a0bc Mon Sep 17 00:00:00 2001
From: Francisco Giordano <frangio.1@gmail.com>
Date: Thu, 20 May 2021 11:40:18 -0300
Subject: [PATCH] reserve unchecked for when guarded by explicit require
 (#2685)

---
 contracts/token/ERC20/ERC20.sol   | 2 +-
 contracts/token/ERC777/ERC777.sol | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/token/ERC20/ERC20.sol b/contracts/token/ERC20/ERC20.sol
index 74fbdde04..862581f63 100644
--- a/contracts/token/ERC20/ERC20.sol
+++ b/contracts/token/ERC20/ERC20.sol
@@ -267,8 +267,8 @@ contract ERC20 is Context, IERC20, IERC20Metadata {
         require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
         unchecked {
             _balances[account] = accountBalance - amount;
-            _totalSupply -= amount;
         }
+        _totalSupply -= amount;
 
         emit Transfer(account, address(0), amount);
     }
diff --git a/contracts/token/ERC777/ERC777.sol b/contracts/token/ERC777/ERC777.sol
index 1743cbdcd..1666ec671 100644
--- a/contracts/token/ERC777/ERC777.sol
+++ b/contracts/token/ERC777/ERC777.sol
@@ -421,8 +421,8 @@ contract ERC777 is Context, IERC777, IERC20 {
         require(fromBalance >= amount, "ERC777: burn amount exceeds balance");
         unchecked {
             _balances[from] = fromBalance - amount;
-            _totalSupply -= amount;
         }
+        _totalSupply -= amount;
 
         emit Burned(operator, from, amount, data, operatorData);
         emit Transfer(from, address(0), amount);