diff --git a/Charts/Classes/Charts/BarLineChartViewBase.swift b/Charts/Classes/Charts/BarLineChartViewBase.swift
index a1461c5b41..1147abf6dc 100644
--- a/Charts/Classes/Charts/BarLineChartViewBase.swift
+++ b/Charts/Classes/Charts/BarLineChartViewBase.swift
@@ -984,7 +984,7 @@ public class BarLineChartViewBase: ChartViewBase, UIGestureRecognizerDelegate
             
             //address UITableViewWrepperView bug, 
             //if there is two scrollview together, we pick the outer one
-            var  scrollViewSuper = scrollView?.superview
+            let  scrollViewSuper = scrollView?.superview
             if scrollViewSuper!.isKindOfClass(UIScrollView) {
                 scrollView = scrollViewSuper
             }