diff --git a/eth2/state_processing/src/per_slot_processing.rs b/eth2/state_processing/src/per_slot_processing.rs
index 8dbf65fa7..8f9606723 100644
--- a/eth2/state_processing/src/per_slot_processing.rs
+++ b/eth2/state_processing/src/per_slot_processing.rs
@@ -1,5 +1,5 @@
 use crate::*;
-use tree_hash::{SignedRoot, TreeHash};
+use tree_hash::SignedRoot;
 use types::*;
 
 #[derive(Debug, PartialEq)]
@@ -24,7 +24,6 @@ pub fn per_slot_processing(state: &mut BeaconState, spec: &ChainSpec) -> Result<
 }
 
 fn cache_state(state: &mut BeaconState, spec: &ChainSpec) -> Result<(), Error> {
-    // let previous_slot_state_root = Hash256::from_slice(&state.tree_hash_root()[..]);
     let previous_slot_state_root = state.update_tree_hash_cache()?;
 
     // Note: increment the state slot here to allow use of our `state_root` and `block_root`