diff --git a/jspp.js b/jspp.js
index 50d44b4..00407d5 100644
--- a/jspp.js
+++ b/jspp.js
@@ -34,6 +34,8 @@ class JSPlusPlus {
             }
           
             sieve(siveTo) {
+              const helpers = new JSPlusPlus.General.Helpers
+              const isPrime = helpers.isPrime
               let primes = []
               siveTo = Number(siveTo)