--- a/tests/src/util/helpers.ts
+++ b/tests/src/util/helpers.ts
@@ -21,6 +21,8 @@
 chai.use(chaiAsPromised);
 const expect = chai.expect;
 
+export const U128_MAX = (1n << 128n) - 1n;
+
 type GenericResult = {
   success: boolean,
 };