diff --git a/beacon_node/beacon_chain/src/test_utils.rs b/beacon_node/beacon_chain/src/test_utils.rs
index a523e55bc..8ede8672e 100644
--- a/beacon_node/beacon_chain/src/test_utils.rs
+++ b/beacon_node/beacon_chain/src/test_utils.rs
@@ -1926,8 +1926,9 @@ where
         chain_dump
             .iter()
             .cloned()
-            .map(|checkpoint| checkpoint.beacon_state.finalized_checkpoint().root.into())
-            .filter(|block_hash| *block_hash != Hash256::zero().into())
+            .map(|checkpoint| checkpoint.beacon_state.finalized_checkpoint().root)
+            .filter(|block_hash| *block_hash != Hash256::zero())
+            .map(|hash| hash.into())
             .collect()
     }
 
diff --git a/beacon_node/beacon_chain/tests/op_verification.rs b/beacon_node/beacon_chain/tests/op_verification.rs
index ef62e292b..f4af49071 100644
--- a/beacon_node/beacon_chain/tests/op_verification.rs
+++ b/beacon_node/beacon_chain/tests/op_verification.rs
@@ -8,7 +8,6 @@ use beacon_chain::test_utils::{
 };
 use lazy_static::lazy_static;
 use sloggers::{null::NullLoggerBuilder, Build};
-use slot_clock::TestingSlotClock;
 use std::sync::Arc;
 use store::{LevelDB, StoreConfig};
 use tempfile::{tempdir, TempDir};
@@ -23,7 +22,7 @@ lazy_static! {
 }
 
 type E = MinimalEthSpec;
-type TestHarness = BeaconChainHarness<DiskHarnessType<E, TestingSlotClock>>;
+type TestHarness = BeaconChainHarness<DiskHarnessType<E>>;
 type HotColdDB = store::HotColdDB<E, LevelDB<E>, LevelDB<E>>;
 
 fn get_store(db_path: &TempDir) -> Arc<HotColdDB> {
diff --git a/beacon_node/beacon_chain/tests/store_tests.rs b/beacon_node/beacon_chain/tests/store_tests.rs
index 5b55c99d9..6718791d7 100644
--- a/beacon_node/beacon_chain/tests/store_tests.rs
+++ b/beacon_node/beacon_chain/tests/store_tests.rs
@@ -18,7 +18,6 @@ use lazy_static::lazy_static;
 use logging::test_logger;
 use maplit::hashset;
 use rand::Rng;
-use slot_clock::TestingSlotClock;
 use state_processing::BlockReplayer;
 use std::collections::HashMap;
 use std::collections::HashSet;
@@ -45,7 +44,7 @@ lazy_static! {
 }
 
 type E = MinimalEthSpec;
-type TestHarness = BeaconChainHarness<DiskHarnessType<E, TestingSlotClock>>;
+type TestHarness = BeaconChainHarness<DiskHarnessType<E>>;
 
 fn get_store(db_path: &TempDir) -> Arc<HotColdDB<E, LevelDB<E>, LevelDB<E>>> {
     get_store_with_spec(db_path, test_spec::<E>())
@@ -2118,7 +2117,7 @@ async fn weak_subjectivity_sync() {
 
     // Initialise a new beacon chain from the finalized checkpoint
     let beacon_chain = Arc::new(
-        BeaconChainBuilder::<DiskHarnessType<E, TestingSlotClock>>::new(MinimalEthSpec)
+        BeaconChainBuilder::<DiskHarnessType<E>>::new(MinimalEthSpec)
             .store(store.clone())
             .custom_spec(test_spec::<E>())
             .task_executor(harness.chain.task_executor.clone())
@@ -2315,13 +2314,12 @@ async fn finalizes_after_resuming_from_db() {
 
     let original_chain = harness.chain;
 
-    let resumed_harness =
-        BeaconChainHarness::<DiskHarnessType<E, TestingSlotClock>>::builder(MinimalEthSpec)
-            .default_spec()
-            .keypairs(KEYPAIRS[0..validator_count].to_vec())
-            .resumed_disk_store(store)
-            .mock_execution_layer()
-            .build();
+    let resumed_harness = BeaconChainHarness::<DiskHarnessType<E>>::builder(MinimalEthSpec)
+        .default_spec()
+        .keypairs(KEYPAIRS[0..validator_count].to_vec())
+        .resumed_disk_store(store)
+        .mock_execution_layer()
+        .build();
 
     assert_chains_pretty_much_the_same(&original_chain, &resumed_harness.chain);
 
diff --git a/beacon_node/http_api/tests/common.rs b/beacon_node/http_api/tests/common.rs
index 5cc9ab2ef..d0eabcc26 100644
--- a/beacon_node/http_api/tests/common.rs
+++ b/beacon_node/http_api/tests/common.rs
@@ -22,7 +22,6 @@ use logging::test_logger;
 use network::{NetworkReceivers, NetworkSenders};
 use sensitive_url::SensitiveUrl;
 use slog::Logger;
-use slot_clock::TestingSlotClock;
 use std::future::Future;
 use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::sync::Arc;
@@ -56,9 +55,9 @@ pub struct ApiServer<E: EthSpec, SFut: Future<Output = ()>> {
     pub external_peer_id: PeerId,
 }
 
-type HarnessBuilder<E> = Builder<EphemeralHarnessType<E>, TestingSlotClock>;
+type HarnessBuilder<E> = Builder<EphemeralHarnessType<E>>;
 type Initializer<E> = Box<dyn FnOnce(HarnessBuilder<E>) -> HarnessBuilder<E>>;
-type Mutator<E> = BoxedMutator<E, MemoryStore<E>, MemoryStore<E>, TestingSlotClock>;
+type Mutator<E> = BoxedMutator<E, MemoryStore<E>, MemoryStore<E>>;
 
 impl<E: EthSpec> InteractiveTester<E> {
     pub async fn new(spec: Option<ChainSpec>, validator_count: usize) -> Self {
diff --git a/beacon_node/network/src/service/tests.rs b/beacon_node/network/src/service/tests.rs
index 57be233d5..a21424d7d 100644
--- a/beacon_node/network/src/service/tests.rs
+++ b/beacon_node/network/src/service/tests.rs
@@ -3,7 +3,7 @@
 mod tests {
     use crate::persisted_dht::load_dht;
     use crate::{NetworkConfig, NetworkService};
-    use beacon_chain::test_utils::{BeaconChainHarness, EphemeralHarnessType};
+    use beacon_chain::test_utils::EphemeralHarnessType;
     use lighthouse_network::Enr;
     use slog::{o, Drain, Level, Logger};
     use sloggers::{null::NullLoggerBuilder, Build};
@@ -12,6 +12,8 @@ mod tests {
     use tokio::runtime::Runtime;
     use types::MinimalEthSpec as E;
 
+    type BeaconChainHarness = beacon_chain::test_utils::BeaconChainHarness<EphemeralHarnessType<E>>;
+
     fn get_logger(actual_log: bool) -> Logger {
         if actual_log {
             let drain = {
@@ -34,7 +36,7 @@ mod tests {
     fn test_dht_persistence() {
         let log = get_logger(false);
 
-        let beacon_chain = BeaconChainHarness::EphemeralHarnessType::<E>::builder(E)
+        let beacon_chain = BeaconChainHarness::builder(E)
             .default_spec()
             .deterministic_keypairs(8)
             .fresh_ephemeral_store()
diff --git a/common/slot_clock/src/lib.rs b/common/slot_clock/src/lib.rs
index 183f5c931..760b2f9cd 100644
--- a/common/slot_clock/src/lib.rs
+++ b/common/slot_clock/src/lib.rs
@@ -7,8 +7,8 @@ mod system_time_slot_clock;
 
 use std::time::Duration;
 
-pub use crate::manual_slot_clock::ManualSlotClock;
 pub use crate::manual_slot_clock::ManualSlotClock as TestingSlotClock;
+pub use crate::manual_slot_clock::ManualSlotClock;
 pub use crate::system_time_slot_clock::SystemTimeSlotClock;
 pub use metrics::scrape_for_metrics;
 use types::consts::merge::INTERVALS_PER_SLOT;