diff --git a/packages/rln/src/utils/bytes.ts b/packages/rln/src/utils/bytes.ts
index 76ccc1b68b..279a2b3822 100644
--- a/packages/rln/src/utils/bytes.ts
+++ b/packages/rln/src/utils/bytes.ts
@@ -65,16 +65,8 @@ export function buildBigIntFromUint8Array(
   array: Uint8Array,
   byteOffset: number = 0
 ): bigint {
-  // Convert byte array to BigInt in big-endian format (to match nwaku)
-  let result = 0n;
-  // Process all 32 bytes (or the available bytes if less)
-  const length = Math.min(array.length - byteOffset, 32);
-
-  for (let i = 0; i < length; i++) {
-    result = (result << 8n) | BigInt(array[byteOffset + i]);
-  }
-
-  return result;
+  const dataView = new DataView(array.buffer);
+  return dataView.getBigUint64(byteOffset, true);
 }
 
 /**