diff --git a/lib/ain-ocean/src/indexer/oracle.rs b/lib/ain-ocean/src/indexer/oracle.rs
index 343b4831ae..77ab02710f 100644
--- a/lib/ain-ocean/src/indexer/oracle.rs
+++ b/lib/ain-ocean/src/indexer/oracle.rs
@@ -53,7 +53,7 @@ impl Index for AppointOracle {
         };
         services.oracle.by_id.put(&oracle_id, &oracle)?;
 
-        let oracle_history_id = (oracle_id, ctx.block.height.to_be_bytes());
+        let oracle_history_id = (oracle_id, ctx.block.height);
         services
             .oracle_history
             .by_id
@@ -88,7 +88,7 @@ impl Index for AppointOracle {
         services
             .oracle_history
             .by_id
-            .delete(&(oracle_id, context.block.height.to_be_bytes()))?;
+            .delete(&(oracle_id, context.block.height))?;
 
         for currency_pair in self.price_feeds.iter().rev() {
             let token_currency_id = (
@@ -184,7 +184,7 @@ impl Index for UpdateOracle {
         services
             .oracle_history
             .by_id
-            .put(&(oracle_id, ctx.block.height.to_be_bytes()), &oracle)?;
+            .put(&(oracle_id, ctx.block.height), &oracle)?;
 
         let (_, previous) =
             get_previous_oracle(services, oracle_id)?.context(NotFoundIndexSnafu {
@@ -220,7 +220,7 @@ impl Index for UpdateOracle {
         services
             .oracle_history
             .by_id
-            .delete(&(oracle_id, context.block.height.to_be_bytes()))?;
+            .delete(&(oracle_id, context.block.height))?;
 
         let price_feeds = self.price_feeds.as_ref();
         for pair in price_feeds.iter().rev() {
@@ -739,7 +739,7 @@ fn get_previous_oracle(
     let previous = services
         .oracle_history
         .by_id
-        .list(Some((oracle_id, [0xffu8; 4])), SortOrder::Descending)?
+        .list(Some((oracle_id, u32::MAX)), SortOrder::Descending)?
         .next()
         .transpose()?;
 
diff --git a/lib/ain-ocean/src/model/oracle.rs b/lib/ain-ocean/src/model/oracle.rs
index c15c3f7f69..6c4c0b9548 100644
--- a/lib/ain-ocean/src/model/oracle.rs
+++ b/lib/ain-ocean/src/model/oracle.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use super::BlockContext;
 
-pub type OracleHistoryId = (Txid, [u8; 4]); //oracleId-height
+pub type OracleHistoryId = (Txid, u32); //oracleId-height
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
 #[serde(rename_all = "camelCase")]
diff --git a/lib/ain-ocean/src/storage/mod.rs b/lib/ain-ocean/src/storage/mod.rs
index 0d6c449636..92ef6cfc9b 100644
--- a/lib/ain-ocean/src/storage/mod.rs
+++ b/lib/ain-ocean/src/storage/mod.rs
@@ -175,6 +175,28 @@ define_table! {
     pub struct OracleHistory {
         key_type = model::OracleHistoryId,
         value_type = model::Oracle,
+        custom_key = {
+            fn key(index: &Self::Index) -> DBResult<Vec<u8>> {
+                let (txid, height) = index; // txid, u32
+                let mut vec = txid.as_byte_array().to_vec();
+                vec.extend_from_slice(&height.to_be_bytes());
+                Ok(vec)
+            }
+
+            fn get_key(raw_key: Box<[u8]>) -> DBResult<Self::Index> {
+                if raw_key.len() != 36 {
+                    return Err(DBError::WrongKeyLength);
+                }
+                let mut txid_array = [0u8; 32];
+                txid_array.copy_from_slice(&raw_key[..32]);
+                let mut height_array = [0u8; 4];
+                height_array.copy_from_slice(&raw_key[32..]);
+
+                let txid = Txid::from_byte_array(txid_array);
+                let height = u32::from_be_bytes(height_array);
+                Ok((txid, height))
+            }
+        },
     }
 }