diff --git a/runtime/src/accounts_index.rs b/runtime/src/accounts_index.rs
index d4655f31b3..cedcdb0e9a 100644
--- a/runtime/src/accounts_index.rs
+++ b/runtime/src/accounts_index.rs
@@ -48,7 +48,9 @@ pub type AccountMap<V> = InMemAccountsIndex<V>;
 
 pub(crate) type AccountMapEntry<T> = Arc<AccountMapEntryInner<T>>;
 
-pub trait IsCached: 'static + Clone + Debug + PartialEq + ZeroLamport + Copy + Default {
+pub trait IsCached:
+    'static + Clone + Debug + PartialEq + ZeroLamport + Copy + Default + Sync + Send
+{
     fn is_cached(&self) -> bool;
 }
 
@@ -694,7 +696,7 @@ pub struct AccountsIndex<T: IsCached> {
     // scanning the fork with that Bank at the tip is no longer possible.
     pub removed_bank_ids: Mutex<HashSet<BankId>>,
 
-    storage: AccountsIndexStorage,
+    storage: AccountsIndexStorage<T>,
 }
 
 impl<T: IsCached> AccountsIndex<T> {
@@ -725,7 +727,11 @@ impl<T: IsCached> AccountsIndex<T> {
 
     fn allocate_accounts_index(
         config: Option<AccountsIndexConfig>,
-    ) -> (LockMapType<T>, PubkeyBinCalculator16, AccountsIndexStorage) {
+    ) -> (
+        LockMapType<T>,
+        PubkeyBinCalculator16,
+        AccountsIndexStorage<T>,
+    ) {
         let bins = config
             .and_then(|config| config.bins)
             .unwrap_or(BINS_DEFAULT);
diff --git a/runtime/src/accounts_index_storage.rs b/runtime/src/accounts_index_storage.rs
index d2fda9b24e..e1567ed4e0 100644
--- a/runtime/src/accounts_index_storage.rs
+++ b/runtime/src/accounts_index_storage.rs
@@ -1,3 +1,4 @@
+use crate::accounts_index::IsCached;
 use crate::bucket_map_holder::BucketMapHolder;
 use crate::waitable_condvar::WaitableCondvar;
 use std::{
@@ -14,17 +15,17 @@ use std::{
 //  and it will stop all the background threads and join them.
 
 #[derive(Debug, Default)]
-pub struct AccountsIndexStorage {
+pub struct AccountsIndexStorage<T: IsCached> {
     // for managing the bg threads
     exit: Arc<AtomicBool>,
     wait: Arc<WaitableCondvar>,
     handle: Option<JoinHandle<()>>,
 
     // eventually the backing storage
-    storage: Arc<BucketMapHolder>,
+    storage: Arc<BucketMapHolder<T>>,
 }
 
-impl Drop for AccountsIndexStorage {
+impl<T: IsCached> Drop for AccountsIndexStorage<T> {
     fn drop(&mut self) {
         self.exit.store(true, Ordering::Relaxed);
         self.wait.notify_all();
@@ -34,8 +35,8 @@ impl Drop for AccountsIndexStorage {
     }
 }
 
-impl AccountsIndexStorage {
-    pub fn new() -> AccountsIndexStorage {
+impl<T: IsCached> AccountsIndexStorage<T> {
+    pub fn new() -> AccountsIndexStorage<T> {
         let storage = Arc::new(BucketMapHolder::new());
         let storage_ = storage.clone();
         let exit = Arc::new(AtomicBool::default());
@@ -59,7 +60,7 @@ impl AccountsIndexStorage {
         }
     }
 
-    pub fn storage(&self) -> &Arc<BucketMapHolder> {
+    pub fn storage(&self) -> &Arc<BucketMapHolder<T>> {
         &self.storage
     }
 }
diff --git a/runtime/src/bucket_map_holder.rs b/runtime/src/bucket_map_holder.rs
index 29de87ea29..2709eed1e4 100644
--- a/runtime/src/bucket_map_holder.rs
+++ b/runtime/src/bucket_map_holder.rs
@@ -1,3 +1,4 @@
+use crate::accounts_index::IsCached;
 use crate::bucket_map_holder_stats::BucketMapHolderStats;
 use crate::waitable_condvar::WaitableCondvar;
 use std::fmt::Debug;
@@ -7,15 +8,14 @@ use std::time::Duration;
 
 // will eventually hold the bucket map
 #[derive(Debug, Default)]
-pub struct BucketMapHolder {
+pub struct BucketMapHolder<T: IsCached> {
     pub stats: BucketMapHolderStats,
+    _phantom: std::marker::PhantomData<T>,
 }
 
-impl BucketMapHolder {
+impl<T: IsCached> BucketMapHolder<T> {
     pub fn new() -> Self {
-        Self {
-            stats: BucketMapHolderStats::default(),
-        }
+        Self::default()
     }
 
     // intended to execute in a bg thread
diff --git a/runtime/src/in_mem_accounts_index.rs b/runtime/src/in_mem_accounts_index.rs
index 06dfdf7767..4f19acc7e1 100644
--- a/runtime/src/in_mem_accounts_index.rs
+++ b/runtime/src/in_mem_accounts_index.rs
@@ -22,12 +22,12 @@ type K = Pubkey;
 pub struct InMemAccountsIndex<T: IsCached> {
     // backing store
     map: HashMap<Pubkey, AccountMapEntry<T>>,
-    storage: Arc<BucketMapHolder>,
+    storage: Arc<BucketMapHolder<T>>,
     bin: usize,
 }
 
 impl<T: IsCached> InMemAccountsIndex<T> {
-    pub fn new(storage: &AccountsIndexStorage, bin: usize) -> Self {
+    pub fn new(storage: &AccountsIndexStorage<T>, bin: usize) -> Self {
         Self {
             map: HashMap::new(),
             storage: storage.storage().clone(),
@@ -35,7 +35,7 @@ impl<T: IsCached> InMemAccountsIndex<T> {
         }
     }
 
-    pub fn new_bucket_map_holder() -> Arc<BucketMapHolder> {
+    pub fn new_bucket_map_holder() -> Arc<BucketMapHolder<T>> {
         Arc::new(BucketMapHolder::new())
     }