diff --git a/contracts/libraries/TwabLib.sol b/contracts/libraries/TwabLib.sol
index 46a97fec..3fc21db5 100644
--- a/contracts/libraries/TwabLib.sol
+++ b/contracts/libraries/TwabLib.sol
@@ -97,7 +97,7 @@ library TwabLib {
     */
     function decreaseBalance(
         Account storage _account,
-        uint256 _amount,
+        uint208 _amount,
         string memory _revertMessage,
         uint32 _currentTime
     )
@@ -113,7 +113,7 @@ library TwabLib {
         require(_accountDetails.balance >= _amount, _revertMessage);
 
         (accountDetails, twab, isNew) = _nextTwab(_account.twabs, _accountDetails, _currentTime);
-        accountDetails.balance = (_accountDetails.balance - _amount).toUint208();
+        accountDetails.balance = _accountDetails.balance - _amount;
     }
 
     /** @notice Calculates the average balance held by a user for a given time frame.