diff --git a/subgraphs/magicswap/schema.graphql b/subgraphs/magicswap/schema.graphql
index 15458b1..692b1cf 100644
--- a/subgraphs/magicswap/schema.graphql
+++ b/subgraphs/magicswap/schema.graphql
@@ -106,7 +106,7 @@ type VaultReserveItem @entity {
   vault: Token!
   collection: Collection!
   tokenId: BigInt!
-  amount: Int!
+  amount: BigInt!
 }
 
 type Pair @entity {
@@ -214,7 +214,7 @@ type TransactionItem @entity(immutable: true) {
   vault: Token!
   collection: Collection!
   tokenId: BigInt!
-  amount: Int!
+  amount: BigInt!
 }
 
 type Incentive @entity {
diff --git a/subgraphs/magicswap/src/helpers.ts b/subgraphs/magicswap/src/helpers.ts
index 4dc2aee..e630f9a 100644
--- a/subgraphs/magicswap/src/helpers.ts
+++ b/subgraphs/magicswap/src/helpers.ts
@@ -195,7 +195,7 @@ export const getOrCreateVaultReserveItem = (
     reserveItem.vault = vault;
     reserveItem.collection = collection;
     reserveItem.tokenId = tokenId;
-    reserveItem.amount = 0;
+    reserveItem.amount = ZERO_BI;
   }
 
   return reserveItem;
diff --git a/subgraphs/magicswap/src/mappings/vault.ts b/subgraphs/magicswap/src/mappings/vault.ts
index 6d8acaf..c70d563 100644
--- a/subgraphs/magicswap/src/mappings/vault.ts
+++ b/subgraphs/magicswap/src/mappings/vault.ts
@@ -63,7 +63,7 @@ export function handleDeposit(event: Deposit): void {
     params.collection,
     params.tokenId
   );
-  reserveItem.amount += params.amount.toI32();
+  reserveItem.amount = reserveItem.amount.plus(params.amount);
   reserveItem.save();
 
   const transaction = getOrCreateTransaction(event);
@@ -77,7 +77,7 @@ export function handleDeposit(event: Deposit): void {
   transactionItem.vault = vault;
   transactionItem.collection = params.collection;
   transactionItem.tokenId = params.tokenId;
-  transactionItem.amount = params.amount.toI32();
+  transactionItem.amount = transactionItem.amount.plus(params.amount);
   transactionItem.save();
 }
 
@@ -90,8 +90,8 @@ export function handleWithdraw(event: Withdraw): void {
     params.collection,
     params.tokenId
   );
-  reserveItem.amount -= params.amount.toI32();
-  if (reserveItem.amount > 0) {
+  reserveItem.amount = reserveItem.amount.minus(params.amount);
+  if (reserveItem.amount.gt(ZERO_BI)) {
     reserveItem.save();
   } else {
     store.remove("VaultReserveItem", reserveItem.id.toHexString());
@@ -111,6 +111,6 @@ export function handleWithdraw(event: Withdraw): void {
   transactionItem.vault = vault;
   transactionItem.collection = params.collection;
   transactionItem.tokenId = params.tokenId;
-  transactionItem.amount = params.amount.toI32();
+  transactionItem.amount = params.amount;
   transactionItem.save();
 }