diff --git a/flake.nix b/flake.nix
index df0d42800..d6862fa51 100644
--- a/flake.nix
+++ b/flake.nix
@@ -52,8 +52,8 @@
         hevm = pkgs: pkgs.lib.pipe ((hsPkgs pkgs).callCabal2nix "hevm" (pkgs.fetchFromGitHub {
           owner = "ethereum";
           repo = "hevm";
-          rev = "release/0.54.2";
-          sha256 = "sha256-h0e6QeMBIUkyANYdrGjrqZ2M4fnODOB0gNPQtsrAiL8=";
+          rev = "5f48aaa93e18cf8f42b46109c04a76234b746dc6";
+          sha256 = "sha256-RNT6ySisP1mdR0NJ1Yyu12A4duzsFCfya+l4CNXHlgQ=";
         }) { secp256k1 = pkgs.secp256k1; })
         ([
           pkgs.haskell.lib.compose.dontCheck
diff --git a/lib/Echidna/Events.hs b/lib/Echidna/Events.hs
index 645112f9b..3b6807ea4 100644
--- a/lib/Echidna/Events.hs
+++ b/lib/Echidna/Events.hs
@@ -17,6 +17,7 @@ import Data.Vector (fromList)
 import EVM (traceForest)
 import EVM.ABI (Event(..), Indexed(..), decodeAbiValue, AbiType(..), AbiValue(..))
 import EVM.Dapp (DappContext(..), DappInfo(..))
+import EVM.Expr (maybeLitWordSimp)
 import EVM.Format (showValues, showError, contractNamePart)
 import EVM.Solidity (SolcContract(..))
 import EVM.Types
@@ -37,7 +38,7 @@ extractEvents decodeErrors dappInfo vm =
   where
   showTrace trace =
     let ?context = DappContext { info = dappInfo, contracts = vm.env.contracts, labels = vm.labels } in
-    let codehash' = fromJust $ maybeLitWord trace.contract.codehash
+    let codehash' = fromJust $ maybeLitWordSimp trace.contract.codehash
         maybeContractName = maybeContractNameFromCodeHash dappInfo codehash'
     in case trace.tracedata of
       EventTrace addr bytes (topic:_) ->
diff --git a/lib/Echidna/SourceMapping.hs b/lib/Echidna/SourceMapping.hs
index e0c476d85..02c9f1253 100644
--- a/lib/Echidna/SourceMapping.hs
+++ b/lib/Echidna/SourceMapping.hs
@@ -11,8 +11,9 @@ import Data.Maybe (mapMaybe)
 import Data.Vector qualified as V
 import Echidna.Symbolic (forceWord)
 import EVM.Dapp (DappInfo(..), findSrc)
+import EVM.Expr (maybeLitByteSimp)
 import EVM.Solidity (SolcContract(..))
-import EVM.Types (Contract(..), ContractCode(..), RuntimeCode(..), W256, maybeLitByte)
+import EVM.Types (Contract(..), ContractCode(..), RuntimeCode(..), W256)
 
 -- | Map from contracts' codehashes to their compile-time codehash.
 -- This is relevant when the immutables solidity feature is used;
@@ -80,7 +81,7 @@ findSrcByMetadata contr dapp = find compareMetadata (snd <$> Map.elems dapp.solc
     (UnknownCode _) -> Nothing
     (InitCode c _) -> Just c
     (RuntimeCode (ConcreteRuntimeCode c)) -> Just c
-    (RuntimeCode (SymbolicRuntimeCode c)) -> Just $ BS.pack $ mapMaybe maybeLitByte $ V.toList c
+    (RuntimeCode (SymbolicRuntimeCode c)) -> Just $ BS.pack $ mapMaybe maybeLitByteSimp $ V.toList c
 
 getBytecodeMetadata :: ByteString -> ByteString
 getBytecodeMetadata bs =
diff --git a/lib/Echidna/SymExec.hs b/lib/Echidna/SymExec.hs
index 3fd67f9c4..8ae6567d1 100644
--- a/lib/Echidna/SymExec.hs
+++ b/lib/Echidna/SymExec.hs
@@ -137,6 +137,7 @@ vmMakeSymbolic vm
   , currentFork    = vm.currentFork
   , labels         = vm.labels
   , osEnv          = vm.osEnv
+  , freshVar       = vm.freshVar
   }
 
 frameStateMakeSymbolic :: FrameState Concrete s -> FrameState Symbolic s
diff --git a/stack.yaml b/stack.yaml
index 3594dc184..52e5283da 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -5,7 +5,7 @@ packages:
 
 extra-deps:
 - git: https://github.com/ethereum/hevm.git
-  commit: 037ff11779d0089378f01cb103db1171dc642be2
+  commit: 5f48aaa93e18cf8f42b46109c04a76234b746dc6
 
 - smt2-parser-0.1.0.1@sha256:1e1a4565915ed851c13d1e6b8bb5185cf5d454da3b43170825d53e221f753d77,1421
 - spawn-0.3@sha256:b91e01d8f2b076841410ae284b32046f91471943dc799c1af77d666c72101f02,1162