diff --git a/src/ReservoirPriceOracle.sol b/src/ReservoirPriceOracle.sol
index 824f411..76bbc1b 100644
--- a/src/ReservoirPriceOracle.sol
+++ b/src/ReservoirPriceOracle.sol
@@ -507,15 +507,14 @@ contract ReservoirPriceOracle is IPriceOracle, IReservoirPriceOracle, Owned(msg.
     }
 
     /// @notice Sets the pair to serve as price feed for a given route.
-    // TODO: Should be TokenA & TokenB because this function sorts them?
-    function designatePair(address aToken0, address aToken1, ReservoirPair aPair) external onlyOwner {
-        (aToken0, aToken1) = aToken0.sortTokens(aToken1);
-        // TODO: Should be require as it's possible to fail right? Generally
-        // assert is used for symbolic provers to find invariants they can break.
-        assert(aToken0 == address(aPair.token0()) && aToken1 == address(aPair.token1()));
+    function designatePair(address aTokenA, address aTokenB, ReservoirPair aPair) external onlyOwner {
+        (aTokenA, aTokenB) = aTokenA.sortTokens(aTokenB);
+        if (aTokenA != address(aPair.token0()) || aTokenB != address(aPair.token1())) {
+            revert OracleErrors.IncorrectTokensDesignatePair();
+        }
 
-        pairs[aToken0][aToken1] = aPair;
-        emit DesignatePair(aToken0, aToken1, aPair);
+        pairs[aTokenA][aTokenB] = aPair;
+        emit DesignatePair(aTokenA, aTokenB, aPair);
     }
 
     function undesignatePair(address aToken0, address aToken1) external onlyOwner {
diff --git a/src/libraries/OracleErrors.sol b/src/libraries/OracleErrors.sol
index 3d1fa97..3a70260 100644
--- a/src/libraries/OracleErrors.sol
+++ b/src/libraries/OracleErrors.sol
@@ -4,6 +4,7 @@ pragma solidity ^0.8.0;
 /// @dev Collection of all oracle related errors.
 library OracleErrors {
     // config errors
+    error IncorrectTokensDesignatePair();
     error InvalidRoute();
     error InvalidRouteLength();
     error InvalidTwapPeriod();
diff --git a/test/unit/ReservoirPriceOracle.t.sol b/test/unit/ReservoirPriceOracle.t.sol
index f6c9c50..82331f0 100644
--- a/test/unit/ReservoirPriceOracle.t.sol
+++ b/test/unit/ReservoirPriceOracle.t.sol
@@ -925,7 +925,7 @@ contract ReservoirPriceOracleTest is BaseTest {
 
     function testDesignatePair_IncorrectPair() external {
         // act & assert
-        vm.expectRevert();
+        vm.expectRevert(OracleErrors.IncorrectTokensDesignatePair.selector);
         _oracle.designatePair(address(_tokenA), address(_tokenC), _pair);
     }