--- a/tests/src/util/helpers.ts
+++ b/tests/src/util/helpers.ts
@@ -556,7 +556,7 @@
                       tokenId: number,
                       sender: IKeyringPair,
                       recipient: IKeyringPair,
-                      value: number = 1,
+                      value: number | bigint = 1,
                       type: string = 'NFT') {
   await usingApi(async (api: ApiPromise) => {
     let balanceBefore = new BN(0);
@@ -574,7 +574,7 @@
     }
     if (type === 'Fungible') {
       const balanceAfter = await api.query.nft.balance(collectionId, recipient.address) as unknown as BN;
-      expect(balanceAfter.sub(balanceBefore).toNumber()).to.be.equal(value);
+      expect(balanceAfter.sub(balanceBefore).toString()).to.be.equal(value.toString());
     }
     if (type === 'ReFungible') {
       const nftItemData =