diff --git a/packages/proof/src/hash.ts b/packages/proof/src/hash.ts
index 6f9285ae5..a320fafb5 100644
--- a/packages/proof/src/hash.ts
+++ b/packages/proof/src/hash.ts
@@ -9,5 +9,9 @@ import { NumericString } from "snarkjs"
  * @returns The message digest.
  */
 export default function hash(message: BigNumberish): NumericString {
-    return (BigInt(keccak256(toBeHex(message, 32))) >> 8n).toString()
+    // SNARK scalar field modulus (Baby Jubjub curve)
+    const SNARK_SCALAR_FIELD = 21888242871839275222246405745257275088548364400416034343698204186575808495617n
+    
+    const hashValue = BigInt(keccak256(toBeHex(message, 32)))
+    return (hashValue % SNARK_SCALAR_FIELD).toString()
 }