diff --git a/rvsol/src/Step.sol b/rvsol/src/Step.sol
index f6d408a4..bd41ab31 100644
--- a/rvsol/src/Step.sol
+++ b/rvsol/src/Step.sol
@@ -6,11 +6,13 @@ import { PreimageKeyLib } from "./PreimageKeyLib.sol";
 
 contract Step {
     IPreimageOracle public preimageOracle;
-    address public preimageKeyLib;
 
     constructor(IPreimageOracle _preimageOracle) {
         preimageOracle = _preimageOracle;
-        preimageKeyLib = address(PreimageKeyLib);
+    }
+
+    function localize(bytes32 _key, bytes32 _localContext) public view returns (bytes32 localizedKey_) {
+        return PreimageKeyLib.localize(_key, _localContext);
     }
 
     // Executes a single RISC-V instruction, starting from
@@ -24,10 +26,6 @@ contract Step {
             function preimageOraclePos() -> out { // slot of preimageOraclePos field
                 out := 0
             }
-            function preimageKeyLibPos() -> out { // slot of preimageKeyLib field
-                out := 1
-            }
-
             //
             // Yul64 - functions to do 64 bit math - see yul64.go
             //
@@ -784,6 +782,21 @@ contract Step {
             }
 
             function localize(preImageKey, localContext_) -> localizedKey {
+                // calling address(this).localize(bytes32,bytes32)
+                // eventually calling PreimageKeyLib.localize(bytes32,bytes32)
+                let memPtr := mload(0x40) // get pointer to free memory for preimage interactions
+                mstore(memPtr, shl(224, 0x1aae47f0)) // (32-4)*8=224: right-pad the function selector, and then store it as prefix
+                mstore(add(memPtr, 0x04), preImageKey)
+                mstore(add(memPtr, 0x24), localContext_)
+                let cgas := 100000 // TODO change call gas
+
+                let res := delegatecall(cgas, address(), memPtr, 0x44, 0x00, 0x20) // output into scratch space
+                if res { // 1 on success
+                    localizedKey := mload(0x00)
+                    leave
+                }
+                revertWithCode(0x1234dead)
+
                 // let addr := sload(preimageKeyLibPos()) // calling PreimageKeyLib.localize(bytes32,bytes32)
                 // let memPtr := mload(0x40) // get pointer to free memory for preimage interactions
                 // mstore(memPtr, shl(224, 0x1aae47f0)) // (32-4)*8=224: right-pad the function selector, and then store it as prefix
@@ -803,15 +816,15 @@ contract Step {
 
                 // // TODO: deduplicate definition of localize using lib
                 // // Grab the current free memory pointer to restore later.
-                let ptr := mload(0x40)
-                // Store the local data key and caller next to each other in memory for hashing.
-                mstore(0, preImageKey)
-                mstore(0x20, caller())
-                mstore(0x40, localContext_)
-                // Localize the key with the above `localize` operation.
-                localizedKey := or(and(keccak256(0, 0x60), not(shl(248, 0xFF))), shl(248, 1))
-                // Restore the free memory pointer.
-                mstore(0x40, ptr)
+                // let ptr := mload(0x40)
+                // // Store the local data key and caller next to each other in memory for hashing.
+                // mstore(0, preImageKey)
+                // mstore(0x20, caller())
+                // mstore(0x40, localContext_)
+                // // Localize the key with the above `localize` operation.
+                // localizedKey := or(and(keccak256(0, 0x60), not(shl(248, 0xFF))), shl(248, 1))
+                // // Restore the free memory pointer.
+                // mstore(0x40, ptr)
             }
 
             function readPreimageValue(addr, count, localContext_) -> out {