diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index 7af64924e4..834b04582d 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -590,6 +590,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                     per_slot_processing(&mut state, &self.spec)?;
                 }
 
+                state.build_committee_cache(RelativeEpoch::Current, &self.spec)?;
+
                 let attestation_slot = state.get_attestation_data_slot(&attestation.data)?;
 
                 // Reject any attestation where the `state` loaded from `data.beacon_block_root`