diff --git a/runtime/src/accounts_db.rs b/runtime/src/accounts_db.rs
index 16183e1024..754bafd825 100644
--- a/runtime/src/accounts_db.rs
+++ b/runtime/src/accounts_db.rs
@@ -1352,7 +1352,7 @@ impl Default for AccountsDb {
         let mut bank_hashes = HashMap::new();
         bank_hashes.insert(0, BankHashInfo::default());
         AccountsDb {
-            accounts_index: AccountsIndex::default(),
+            accounts_index: AccountsIndex::new(crate::accounts_index::BINS_DEFAULT),
             storage: AccountStorage::default(),
             accounts_cache: AccountsCache::default(),
             sender_bg_hasher: None,
diff --git a/runtime/src/accounts_index.rs b/runtime/src/accounts_index.rs
index d9cc992e0b..cfa10708b4 100644
--- a/runtime/src/accounts_index.rs
+++ b/runtime/src/accounts_index.rs
@@ -32,7 +32,7 @@ use std::{
 use thiserror::Error;
 
 pub const ITER_BATCH_SIZE: usize = 1000;
-const BINS_DEFAULT: usize = 16;
+pub const BINS_DEFAULT: usize = 16;
 const BINS_FOR_TESTING: usize = BINS_DEFAULT;
 pub type ScanResult<T> = Result<T, ScanError>;
 pub type SlotList<T> = Vec<(Slot, T)>;
@@ -759,7 +759,7 @@ impl<
         Self::new(BINS_FOR_TESTING)
     }
 
-    fn new(bins: usize) -> Self {
+    pub fn new(bins: usize) -> Self {
         let (account_maps, bin_calculator) = Self::allocate_accounts_index(bins);
         Self {
             account_maps,
@@ -3987,4 +3987,10 @@ pub mod tests {
         assert_eq!(iter.start_bin(), bins - 1); // start at highest possible pubkey, so bins - 1
         assert_eq!(iter.end_bin_inclusive(), bins - 1);
     }
+
+    #[test]
+    #[should_panic(expected = "bins.is_power_of_two()")]
+    fn test_illegal_bins() {
+        AccountsIndex::<bool>::new(3);
+    }
 }