diff --git a/Cargo.lock b/Cargo.lock
index 12b8bbb0e..18e9e8b47 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4285,7 +4285,6 @@ dependencies = [
  "node_test_rig",
  "operation_pool",
  "parking_lot 0.11.0",
- "rayon",
  "remote_beacon_node",
  "rest_types",
  "serde",
diff --git a/beacon_node/rest_api/Cargo.toml b/beacon_node/rest_api/Cargo.toml
index 6d023659c..38a5a1e7d 100644
--- a/beacon_node/rest_api/Cargo.toml
+++ b/beacon_node/rest_api/Cargo.toml
@@ -34,7 +34,6 @@ hex = "0.4.2"
 parking_lot = "0.11.0"
 futures = "0.3.5"
 operation_pool = { path = "../operation_pool" }
-rayon = "1.3.0"
 environment = { path = "../../lighthouse/environment" }
 uhttp_sse = "0.5.1"
 bus = "2.2.3"
diff --git a/beacon_node/rest_api/src/validator.rs b/beacon_node/rest_api/src/validator.rs
index 724719c5d..e1c3c37db 100644
--- a/beacon_node/rest_api/src/validator.rs
+++ b/beacon_node/rest_api/src/validator.rs
@@ -8,7 +8,6 @@ use bls::PublicKeyBytes;
 use eth2_libp2p::PubsubMessage;
 use hyper::Request;
 use network::NetworkMessage;
-use rayon::prelude::*;
 use rest_types::{ValidatorDutiesRequest, ValidatorDutyBytes, ValidatorSubscription};
 use slog::{error, info, trace, warn, Logger};
 use std::sync::Arc;
@@ -437,7 +436,7 @@ pub fn publish_attestations<T: BeaconChainTypes>(
         .map(
             move |attestations: Vec<(Attestation<T::EthSpec>, SubnetId)>| {
                 attestations
-                    .into_par_iter()
+                    .into_iter()
                     .enumerate()
                     .map(|(i, (attestation, subnet_id))| {
                         process_unaggregated_attestation(
@@ -546,7 +545,7 @@ pub fn publish_aggregate_and_proofs<T: BeaconChainTypes>(
         .map(
             move |signed_aggregates: Vec<SignedAggregateAndProof<T::EthSpec>>| {
                 signed_aggregates
-                    .into_par_iter()
+                    .into_iter()
                     .enumerate()
                     .map(|(i, signed_aggregate)| {
                         process_aggregated_attestation(