diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index d281fe666ef..8982884655d 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -1482,7 +1482,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
 
         metrics::stop_timer(fork_choice_register_timer);
 
-        self.head_tracker.register_block(block_root, &block);
         metrics::observe(
             &metrics::OPERATIONS_PER_BLOCK_ATTESTATION,
             block.body.attestations.len() as f64,
@@ -1503,6 +1502,9 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         self.store.put_state(&block.state_root, &state)?;
         self.store.put_block(&block_root, signed_block.clone())?;
 
+        let parent_root = block.parent_root;
+        let slot = block.slot;
+
         self.snapshot_cache
             .try_write_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT)
             .map(|mut snapshot_cache| {
@@ -1522,6 +1524,9 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 );
             });
 
+        self.head_tracker
+            .register_block(block_root, parent_root, slot);
+
         metrics::stop_timer(db_write_timer);
 
         metrics::inc_counter(&metrics::BLOCK_PROCESSING_SUCCESSES);
diff --git a/beacon_node/beacon_chain/src/head_tracker.rs b/beacon_node/beacon_chain/src/head_tracker.rs
index 7f4e64122c4..6c7186ef25a 100644
--- a/beacon_node/beacon_chain/src/head_tracker.rs
+++ b/beacon_node/beacon_chain/src/head_tracker.rs
@@ -2,7 +2,7 @@ use parking_lot::RwLock;
 use ssz_derive::{Decode, Encode};
 use std::collections::HashMap;
 use std::iter::FromIterator;
-use types::{BeaconBlock, EthSpec, Hash256, Slot};
+use types::{Hash256, Slot};
 
 #[derive(Debug, PartialEq)]
 pub enum Error {
@@ -23,10 +23,10 @@ impl HeadTracker {
     /// This function assumes that no block is imported without its parent having already been
     /// imported. It cannot detect an error if this is not the case, it is the responsibility of
     /// the upstream user.
-    pub fn register_block<E: EthSpec>(&self, block_root: Hash256, block: &BeaconBlock<E>) {
+    pub fn register_block(&self, block_root: Hash256, parent_root: Hash256, slot: Slot) {
         let mut map = self.0.write();
-        map.remove(&block.parent_root);
-        map.insert(block_root, block.slot);
+        map.remove(&parent_root);
+        map.insert(block_root, slot);
     }
 
     /// Removes abandoned head.