diff --git a/contracts/sdk/gummyroll/accounts/index.ts b/contracts/sdk/gummyroll/accounts/index.ts
index 90a54a9865e..6e3112af585 100644
--- a/contracts/sdk/gummyroll/accounts/index.ts
+++ b/contracts/sdk/gummyroll/accounts/index.ts
@@ -50,7 +50,7 @@ type MerkleRollHeader = {
 };
 
 type MerkleRoll = {
-  sequenceNumber: BN; // u128
+  sequenceNumber: BN; // u64
   activeIndex: number; // u64
   bufferSize: number; // u64
   changeLogs: ChangeLog[];