diff --git a/contracts/UniswapV2.sol b/contracts/UniswapV2.sol
index aaaf80a..85ee788 100644
--- a/contracts/UniswapV2.sol
+++ b/contracts/UniswapV2.sol
@@ -12,7 +12,7 @@ import "./token/SafeTransfer.sol";
 contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0), SafeTransfer {
     using SafeMath128 for uint128;
     using SafeMath256 for uint256;
-    using UQ104x104 for uint232;
+    using UQ104x104 for uint240;
 
     struct TokenData {
         uint128 token0;
@@ -88,12 +88,12 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0), SafeTran
             uint128 blocksElapsed = (block.number - blockNumberLast).downcast128();
 
             // get the prices according to the reserves as of the last official interaction with the contract
-            uint208 priceToken0 = UQ104x104.encode(reserves.token0).qdiv(reserves.token1);
-            uint208 priceToken1 = UQ104x104.encode(reserves.token1).qdiv(reserves.token0);
+            uint240 priceToken0 = UQ104x104.encode(reserves.token0).qdiv(reserves.token1);
+            uint240 priceToken1 = UQ104x104.encode(reserves.token1).qdiv(reserves.token0);
 
             return (
-                priceToken0Accumulated + (uint240(priceToken0) * blocksElapsed),
-                priceToken1Accumulated + (uint240(priceToken1) * blocksElapsed)
+                priceToken0Accumulated + priceToken0 * blocksElapsed,
+                priceToken1Accumulated + priceToken1 * blocksElapsed
             );
         } else {
             return (
@@ -126,12 +126,12 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0), SafeTran
                 uint32 blocksElapsed = blockNumber - blockNumberLast;
 
                 // get the prices according to the reserves as of the last official interaction with the contract
-                uint208 priceToken0 = UQ104x104.encode(reserves.token0).qdiv(reserves.token1);
-                uint208 priceToken1 = UQ104x104.encode(reserves.token1).qdiv(reserves.token0);
+                uint240 priceToken0 = UQ104x104.encode(reserves.token0).qdiv(reserves.token1);
+                uint240 priceToken1 = UQ104x104.encode(reserves.token1).qdiv(reserves.token0);
 
                 // multiply these prices by the number of elapsed blocks and add to the accumulators
-                priceToken0Accumulated = priceToken0Accumulated + (uint240(priceToken0) * blocksElapsed);
-                priceToken1Accumulated = priceToken1Accumulated + (uint240(priceToken1) * blocksElapsed);
+                priceToken0Accumulated = priceToken0Accumulated + priceToken0 * blocksElapsed;
+                priceToken1Accumulated = priceToken1Accumulated + priceToken1 * blocksElapsed;
             }
 
             // update the last block number
diff --git a/contracts/libraries/UQ104x104.sol b/contracts/libraries/UQ104x104.sol
index 705cffe..07d3dde 100644
--- a/contracts/libraries/UQ104x104.sol
+++ b/contracts/libraries/UQ104x104.sol
@@ -6,29 +6,28 @@ pragma solidity 0.5.12;
 // https://github.com/gnosis/solidity-arithmetic
 
 library UQ104x104 {
-    uint232 constant Q104 = uint232(uint104(-1)) + 1;
+    uint240 constant Q104 = 2**104;
 
     // we want to encode a uint128 `y` s.t. `y := y_encoded / 2**104` (i.e. with a Q104 denominator).
     // in other words, to encode `y` we simply multiply by `2**104`, aka Q104.
     // however, in the case of a traditional UQ104.104, we'd store this output in a 208-bit slot,
     // which would overflow for values of `y` in (`uint104(-1)`, `uint128(-1)`], so instead we need to
     // store the output in 232 bits (TODO check this logic).
-    function encode(uint128 y) internal pure returns (uint232 z) {
-        return uint232(y) * Q104;
+    function encode(uint128 y) internal pure returns (uint240 z) {
+        return uint240(y) * Q104;
     }
 
     // we want to divide a modified UQ104.104 (the output of encode) by an unencoded uint128,
     // and return a traditional Q104. since we're using a modified UQ104.104, though, we need to handle overflows.
     // for the moment, we simply truncate these to 1 and uint208(-1), though it's likely we'll handle this slightly
     // differently in the future
-    function qdiv(uint232 x, uint128 y) internal pure returns (uint208 z) {
-        uint232 temp = x / y;
-        if (temp == 0) {
+    function qdiv(uint240 x, uint128 y) internal pure returns (uint240 z) {
+        z = x / y;
+        
+        if (z == 0) {
             z = 1;
-        } else if (temp > uint208(-1)) {
+        } else if (z > uint208(-1)) {
             z = uint208(-1);
-        } else {
-            z = uint208(temp);
         }
     }
 }