diff --git a/specs/capella/fork-choice.md b/specs/capella/fork-choice.md
index 80bec2933..47acf2cfb 100644
--- a/specs/capella/fork-choice.md
+++ b/specs/capella/fork-choice.md
@@ -34,7 +34,7 @@ def notify_forkchoice_updated(self: ExecutionEngine,
                               head_block_hash: Hash32,
                               safe_block_hash: Hash32,
                               finalized_block_hash: Hash32,
-                              payload_attributes: Optional[PayloadAttributes]) -> Optional[PayloadId]:  # new in Capella
+                              payload_attributes: Optional[PayloadAttributes]) -> Optional[PayloadId]:
     ...
 ```
 
diff --git a/specs/capella/validator.md b/specs/capella/validator.md
index edf5d72bd..5e1f5fd0e 100644
--- a/specs/capella/validator.md
+++ b/specs/capella/validator.md
@@ -87,5 +87,12 @@ def prepare_execution_payload(state: BeaconState,
         suggested_fee_recipient=suggested_fee_recipient,
         withdrawals=get_expected_withdrawals(state),  # [New in Capella]
     )
-    return execution_engine.notify_forkchoice_updated(parent_hash, finalized_block_hash, payload_attributes)
+    # Set safe and head block hashes to the same value
+    return execution_engine.notify_forkchoice_updated(
+        head_block_hash=parent_hash,
+        # TODO: Use `parent_hash` as a stub for now.
+        safe_block_hash=parent_hash,
+        finalized_block_hash=finalized_block_hash,
+        payload_attributes=payload_attributes,
+    )
 ```