diff --git a/src/evm_transition_tool/types.py b/src/evm_transition_tool/types.py
index 0a6341ec5b..b5d95bc4fd 100644
--- a/src/evm_transition_tool/types.py
+++ b/src/evm_transition_tool/types.py
@@ -112,7 +112,7 @@ class Result(CamelModel):
 
     verkle_proof: VerkleProof | None = None
     state_diff: StateDiff | None = None
-    parent_root: Hash | None = None
+    parent_state_root: Hash | None = None
 
 
 class TransitionToolInput(CamelModel):