diff --git a/lib/varDiff.js b/lib/varDiff.js
index f233584..9e1e696 100644
--- a/lib/varDiff.js
+++ b/lib/varDiff.js
@@ -54,7 +54,7 @@ var varDiff = module.exports = function varDiff(ports){
 
         var variance = varDiffOptions.targetTime * (varDiffOptions.variancePercent / 100);
 
-        portsCalcInfo[parseInt(ports)] = {
+        portsCalcInfo[parseInt(port)] = {
             bufferSize: varDiffOptions.retargetTime / varDiffOptions.targetTime * 4,
             tMin: varDiffOptions.targetTime - variance,
             tMax: varDiffOptions.targetTime + variance
@@ -127,4 +127,4 @@ var varDiff = module.exports = function varDiff(ports){
         });
     };
 };
-varDiff.prototype.__proto__ = events.EventEmitter.prototype;
\ No newline at end of file
+varDiff.prototype.__proto__ = events.EventEmitter.prototype;