diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index bafb699c35..233ad5f242 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -102,25 +102,25 @@ where
         block_store.put(&block_root, &ssz_encode(&genesis_block)[..])?;
 
         let block_graph = BlockGraph::new();
-        block_graph.add_leaf(&Hash256::zero(), block_root.clone());
+        block_graph.add_leaf(&Hash256::zero(), block_root);
 
         let finalized_head = RwLock::new(CheckPoint::new(
             genesis_block.clone(),
-            block_root.clone(),
+            block_root,
             genesis_state.clone(),
-            state_root.clone(),
+            state_root,
         ));
         let justified_head = RwLock::new(CheckPoint::new(
             genesis_block.clone(),
-            block_root.clone(),
+            block_root,
             genesis_state.clone(),
-            state_root.clone(),
+            state_root,
         ));
         let canonical_head = RwLock::new(CheckPoint::new(
             genesis_block.clone(),
-            block_root.clone(),
+            block_root,
             genesis_state.clone(),
-            state_root.clone(),
+            state_root,
         ));
         let attestation_aggregator = RwLock::new(AttestationAggregator::new());
 
@@ -134,7 +134,7 @@ where
             justified_head,
             finalized_head,
             canonical_head,
-            spec: spec,
+            spec,
             fork_choice,
         })
     }
@@ -205,7 +205,7 @@ where
         for _ in state_slot..slot {
             self.state
                 .write()
-                .per_slot_processing(head_block_root.clone(), &self.spec)?;
+                .per_slot_processing(head_block_root, &self.spec)?;
         }
         Ok(())
     }
@@ -305,27 +305,25 @@ where
     /// Produce an `AttestationData` that is valid for the present `slot` and given `shard`.
     pub fn produce_attestation_data(&self, shard: u64) -> Result<AttestationData, Error> {
         let justified_slot = self.justified_slot();
-        let justified_block_root = self
+        let justified_block_root = *self
             .state
             .read()
             .get_block_root(justified_slot, &self.spec)
-            .ok_or_else(|| Error::BadRecentBlockRoots)?
-            .clone();
+            .ok_or_else(|| Error::BadRecentBlockRoots)?;
 
-        let epoch_boundary_root = self
+        let epoch_boundary_root = *self
             .state
             .read()
             .get_block_root(
                 self.state.read().current_epoch_start_slot(&self.spec),
                 &self.spec,
             )
-            .ok_or_else(|| Error::BadRecentBlockRoots)?
-            .clone();
+            .ok_or_else(|| Error::BadRecentBlockRoots)?;
 
         Ok(AttestationData {
             slot: self.state.read().slot,
             shard,
-            beacon_block_root: self.head().beacon_block_root.clone(),
+            beacon_block_root: self.head().beacon_block_root,
             epoch_boundary_root,
             shard_block_root: Hash256::zero(),
             latest_crosslink_root: Hash256::zero(),
@@ -447,15 +445,11 @@ where
         let parent_state = self
             .state_store
             .get_reader(&parent_state_root)?
-            .ok_or(Error::DBInconsistent(format!(
-                "Missing state {}",
-                parent_state_root
-            )))?
+            .ok_or_else(|| Error::DBInconsistent(format!("Missing state {}", parent_state_root)))?
             .into_beacon_state()
-            .ok_or(Error::DBInconsistent(format!(
-                "State SSZ invalid {}",
-                parent_state_root
-            )))?;
+            .ok_or_else(|| {
+                Error::DBInconsistent(format!("State SSZ invalid {}", parent_state_root))
+            })?;
 
         // TODO: check the block proposer signature BEFORE doing a state transition. This will
         // significantly lower exposure surface to DoS attacks.
@@ -463,7 +457,7 @@ where
         // Transition the parent state to the present slot.
         let mut state = parent_state;
         for _ in state.slot..present_slot {
-            if let Err(e) = state.per_slot_processing(parent_block_root.clone(), &self.spec) {
+            if let Err(e) = state.per_slot_processing(parent_block_root, &self.spec) {
                 return Ok(BlockProcessingOutcome::InvalidBlock(
                     InvalidBlock::SlotProcessingError(e),
                 ));
@@ -491,8 +485,7 @@ where
         self.state_store.put(&state_root, &ssz_encode(&state)[..])?;
 
         // Update the block DAG.
-        self.block_graph
-            .add_leaf(&parent_block_root, block_root.clone());
+        self.block_graph.add_leaf(&parent_block_root, block_root);
 
         // run the fork_choice add_block logic
         self.fork_choice.add_block(&block, &block_root)?;
@@ -506,7 +499,7 @@ where
                 block.clone(),
                 block_root.clone(),
                 state.clone(),
-                state_root.clone(),
+                state_root,
             );
             // Update the local state variable.
             *self.state.write() = state.clone();
@@ -536,15 +529,13 @@ where
             attestations.len()
         );
 
-        let parent_root = state
-            .get_block_root(state.slot.saturating_sub(1), &self.spec)?
-            .clone();
+        let parent_root = *state.get_block_root(state.slot.saturating_sub(1), &self.spec)?;
 
         let mut block = BeaconBlock {
             slot: state.slot,
             parent_root,
             state_root: Hash256::zero(), // Updated after the state is calculated.
-            randao_reveal: randao_reveal,
+            randao_reveal,
             eth1_data: Eth1Data {
                 // TODO: replace with real data
                 deposit_root: Hash256::zero(),
@@ -554,7 +545,7 @@ where
             body: BeaconBlockBody {
                 proposer_slashings: vec![],
                 casper_slashings: vec![],
-                attestations: attestations,
+                attestations,
                 custody_reseeds: vec![],
                 custody_challenges: vec![],
                 custody_responses: vec![],
@@ -578,11 +569,11 @@ where
 
     // TODO: Left this as is, modify later
     pub fn fork_choice(&mut self) -> Result<(), Error> {
-        let present_head = &self.finalized_head().beacon_block_root.clone();
+        let present_head = self.finalized_head().beacon_block_root;
 
-        let new_head = self.fork_choice.find_head(present_head)?;
+        let new_head = self.fork_choice.find_head(&present_head)?;
 
-        if new_head != *present_head {
+        if new_head != present_head {
             let block = self
                 .block_store
                 .get_deserialized(&new_head)?