diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index 1ce1861cad..a1267f5bb7 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -50,6 +50,10 @@ use crate::{
     log_collector::LogCollector,
     message_processor::{ExecuteDetailsTimings, Executors, MessageProcessor},
     rent_collector::RentCollector,
+    stake_weighted_timestamp::{
+        calculate_stake_weighted_timestamp, MaxAllowableDrift, MAX_ALLOWABLE_DRIFT_PERCENTAGE,
+        MAX_ALLOWABLE_DRIFT_PERCENTAGE_FAST, MAX_ALLOWABLE_DRIFT_PERCENTAGE_SLOW,
+    },
     stakes::Stakes,
     status_cache::{SlotDelta, StatusCache},
     system_instruction_processor::{get_system_account_kind, SystemAccountKind},
@@ -97,10 +101,6 @@ use solana_sdk::{
     slot_hashes::SlotHashes,
     slot_history::SlotHistory,
     stake::{self, state::Delegation},
-    stake_weighted_timestamp::{
-        calculate_stake_weighted_timestamp, MaxAllowableDrift, MAX_ALLOWABLE_DRIFT_PERCENTAGE,
-        MAX_ALLOWABLE_DRIFT_PERCENTAGE_FAST, MAX_ALLOWABLE_DRIFT_PERCENTAGE_SLOW,
-    },
     system_transaction,
     sysvar::{self},
     timing::years_as_slots,
diff --git a/runtime/src/lib.rs b/runtime/src/lib.rs
index ebde96ae41..75ce61d407 100644
--- a/runtime/src/lib.rs
+++ b/runtime/src/lib.rs
@@ -36,6 +36,7 @@ pub mod serde_snapshot;
 pub mod snapshot_package;
 pub mod snapshot_utils;
 pub mod sorted_storages;
+pub mod stake_weighted_timestamp;
 pub mod stakes;
 pub mod status_cache;
 mod system_instruction_processor;
diff --git a/sdk/src/stake_weighted_timestamp.rs b/runtime/src/stake_weighted_timestamp.rs
similarity index 98%
rename from sdk/src/stake_weighted_timestamp.rs
rename to runtime/src/stake_weighted_timestamp.rs
index 44478e2856..6674024686 100644
--- a/sdk/src/stake_weighted_timestamp.rs
+++ b/runtime/src/stake_weighted_timestamp.rs
@@ -11,22 +11,17 @@ use std::{
     time::Duration,
 };
 
-pub const MAX_ALLOWABLE_DRIFT_PERCENTAGE: u32 = 50;
-pub const MAX_ALLOWABLE_DRIFT_PERCENTAGE_FAST: u32 = 25;
-pub const MAX_ALLOWABLE_DRIFT_PERCENTAGE_SLOW: u32 = 80;
-
-pub enum EstimateType {
-    Bounded(MaxAllowableDrift), // Value represents max allowable drift percentage
-    Unbounded,                  // Deprecated.  Remove in the Solana v1.6.0 timeframe
-}
+pub(crate) const MAX_ALLOWABLE_DRIFT_PERCENTAGE: u32 = 50;
+pub(crate) const MAX_ALLOWABLE_DRIFT_PERCENTAGE_FAST: u32 = 25;
+pub(crate) const MAX_ALLOWABLE_DRIFT_PERCENTAGE_SLOW: u32 = 80;
 
 #[derive(Copy, Clone)]
-pub struct MaxAllowableDrift {
+pub(crate) struct MaxAllowableDrift {
     pub fast: u32, // Max allowable drift percentage faster than poh estimate
     pub slow: u32, // Max allowable drift percentage slower than poh estimate
 }
 
-pub fn calculate_stake_weighted_timestamp<I, K, V, T>(
+pub(crate) fn calculate_stake_weighted_timestamp<I, K, V, T>(
     unique_timestamps: I,
     stakes: &HashMap<Pubkey, (u64, T /*Account|ArcVoteAccount*/)>,
     slot: Slot,
diff --git a/sdk/src/lib.rs b/sdk/src/lib.rs
index 7559c41958..ee185b155c 100644
--- a/sdk/src/lib.rs
+++ b/sdk/src/lib.rs
@@ -44,7 +44,6 @@ pub mod secp256k1_instruction;
 pub mod shred_version;
 pub mod signature;
 pub mod signer;
-pub mod stake_weighted_timestamp;
 pub mod system_transaction;
 pub mod timing;
 pub mod transaction;