diff --git a/certora/harness/MorphoHarness.sol b/certora/harness/MorphoHarness.sol
index 600515f4b..8101fc251 100644
--- a/certora/harness/MorphoHarness.sol
+++ b/certora/harness/MorphoHarness.sol
@@ -74,10 +74,8 @@ contract MorphoHarness is Morpho {
         return marketParams.id();
     }
 
-    function optimizedId(MarketParams memory marketParams) external pure returns (Id marketParamsId) {
-        assembly ("memory-safe") {
-            marketParamsId := keccak256(marketParams, mul(5, 32))
-        }
+    function refId(MarketParams memory marketParams) external pure returns (Id marketParamsId) {
+        marketParamsId = Id.wrap(keccak256(abi.encode(marketParams)));
     }
 
     function libMulDivUp(uint256 x, uint256 y, uint256 d) public pure returns (uint256) {
diff --git a/certora/munging.patch b/certora/munging.patch
index 8b490be5c..e69de29bb 100644
--- a/certora/munging.patch
+++ b/certora/munging.patch
@@ -1,14 +0,0 @@
-
-diff -ruN libraries/MarketParamsLib.sol libraries/MarketParamsLib.sol
---- libraries/MarketParamsLib.sol	2023-08-29 09:59:37.937583556 +0200
-+++ libraries/MarketParamsLib.sol	2023-08-29 10:16:10.519752188 +0200
-@@ -10,8 +10,6 @@
- library MarketParamsLib {
-     /// @notice Returns the id of the market `marketParams`.
-     function id(MarketParams memory marketParams) internal pure returns (Id marketParamsId) {
--        assembly ("memory-safe") {
--            marketParamsId := keccak256(marketParams, mul(5, 32))
--        }
-+        marketParamsId = Id.wrap(keccak256(abi.encode(marketParams)));
-     }
- }
diff --git a/certora/specs/LibSummary.spec b/certora/specs/LibSummary.spec
index 784ca38d7..76cb6d80c 100644
--- a/certora/specs/LibSummary.spec
+++ b/certora/specs/LibSummary.spec
@@ -19,7 +19,7 @@ rule checkSummaryMulDivDown(uint256 x, uint256 y, uint256 d) {
     assert result * d <= x * y;
 }
 
-// Check the munging of the MarketParams.id function.
+// Check the optimization of the MarketParams.id function.
 rule checkSummaryId(MorphoHarness.MarketParams marketParams) {
-    assert optimizedId(marketParams) == libId(marketParams);
+    assert libId(marketParams) == refId(marketParams);
 }