diff --git a/Source/Charts/Charts/ChartViewBase.swift b/Source/Charts/Charts/ChartViewBase.swift
index c453aced0c..0fccebc4d2 100644
--- a/Source/Charts/Charts/ChartViewBase.swift
+++ b/Source/Charts/Charts/ChartViewBase.swift
@@ -828,7 +828,7 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate
     /// - Returns: The bitmap that represents the chart.
     @objc open func getChartImage(transparent: Bool) -> NSUIImage?
     {
-        NSUIGraphicsBeginImageContextWithOptions(bounds.size, isOpaque || !transparent, NSUIMainScreen()?.nsuiScale ?? 1.0)
+        NSUIGraphicsBeginImageContextWithOptions(bounds.size, isOpaque || !transparent, NSUIScreen.nsuiMain?.nsuiScale ?? 1.0)
         
         guard let context = NSUIGraphicsGetCurrentContext()
             else { return nil }
diff --git a/Source/Charts/Renderers/PieChartRenderer.swift b/Source/Charts/Renderers/PieChartRenderer.swift
index 0985a3da8d..19ea0d4607 100644
--- a/Source/Charts/Renderers/PieChartRenderer.swift
+++ b/Source/Charts/Renderers/PieChartRenderer.swift
@@ -306,8 +306,8 @@ open class PieChartRenderer: DataRenderer
         // get whole the radius
         let radius = chart.radius
         let rotationAngle = chart.rotationAngle
-        var drawAngles = chart.drawAngles
-        var absoluteAngles = chart.absoluteAngles
+        let drawAngles = chart.drawAngles
+        let absoluteAngles = chart.absoluteAngles
 
         let phaseX = animator.phaseX
         let phaseY = animator.phaseY
@@ -321,14 +321,12 @@ open class PieChartRenderer: DataRenderer
 
         let labelRadius = radius - labelRadiusOffset
 
-        var dataSets = data.dataSets
+        let dataSets = data.dataSets
 
         let yValueSum = (data as! PieChartData).yValueSum
 
         let drawEntryLabels = chart.isDrawEntryLabelsEnabled
         let usePercentValuesEnabled = chart.usePercentValuesEnabled
-        let entryLabelColor = chart.entryLabelColor
-        let entryLabelFont = chart.entryLabelFont
 
         var angle: CGFloat = 0.0
         var xIndex = 0
@@ -353,7 +351,7 @@ open class PieChartRenderer: DataRenderer
             let yValuePosition = dataSet.yValuePosition
 
             let valueFont = dataSet.valueFont
-            let entryLabelFont = dataSet.entryLabelFont
+            let entryLabelFont = dataSet.entryLabelFont ?? chart.entryLabelFont
             let lineHeight = valueFont.lineHeight
 
             guard let formatter = dataSet.valueFormatter else { continue }
@@ -399,7 +397,7 @@ open class PieChartRenderer: DataRenderer
                 let drawYInside = drawValues && yValuePosition == .insideSlice
 
                 let valueTextColor = dataSet.valueTextColorAt(j)
-                let entryLabelColor = dataSet.entryLabelColor
+                let entryLabelColor = dataSet.entryLabelColor ?? chart.entryLabelColor
 
                 if drawXOutside || drawYOutside
                 {
diff --git a/Source/Charts/Renderers/XAxisRendererHorizontalBarChart.swift b/Source/Charts/Renderers/XAxisRendererHorizontalBarChart.swift
index ce777746a0..86c569d9df 100644
--- a/Source/Charts/Renderers/XAxisRendererHorizontalBarChart.swift
+++ b/Source/Charts/Renderers/XAxisRendererHorizontalBarChart.swift
@@ -251,7 +251,7 @@ open class XAxisRendererHorizontalBarChart: XAxisRenderer
             let transformer = self.transformer
             else { return }
         
-        var limitLines = xAxis.limitLines
+        let limitLines = xAxis.limitLines
         
         if limitLines.count == 0
         {
diff --git a/Source/Charts/Renderers/YAxisRenderer.swift b/Source/Charts/Renderers/YAxisRenderer.swift
index 80b492d5ee..9d0017f494 100644
--- a/Source/Charts/Renderers/YAxisRenderer.swift
+++ b/Source/Charts/Renderers/YAxisRenderer.swift
@@ -287,7 +287,7 @@ open class YAxisRenderer: AxisRendererBase
             let transformer = self.transformer
             else { return }
         
-        var limitLines = yAxis.limitLines
+        let limitLines = yAxis.limitLines
         
         if limitLines.count == 0
         {
diff --git a/Source/Charts/Renderers/YAxisRendererHorizontalBarChart.swift b/Source/Charts/Renderers/YAxisRendererHorizontalBarChart.swift
index aaf0cd2553..de4f65e522 100644
--- a/Source/Charts/Renderers/YAxisRendererHorizontalBarChart.swift
+++ b/Source/Charts/Renderers/YAxisRendererHorizontalBarChart.swift
@@ -259,7 +259,7 @@ open class YAxisRendererHorizontalBarChart: YAxisRenderer
             let transformer = self.transformer
             else { return }
         
-        var limitLines = yAxis.limitLines
+        let limitLines = yAxis.limitLines
 
         if limitLines.count <= 0
         {
diff --git a/Source/Charts/Utils/Platform.swift b/Source/Charts/Utils/Platform.swift
index 19fdbf7eec..3722647d3d 100644
--- a/Source/Charts/Utils/Platform.swift
+++ b/Source/Charts/Utils/Platform.swift
@@ -39,11 +39,6 @@ extension UIScreen
     }
 }
 
-func NSUIMainScreen() -> NSUIScreen?
-{
-    return NSUIScreen.main
-}
-
 #endif
 
 #if os(OSX)
@@ -237,9 +232,9 @@ extension NSScrollView
     }
 }
 
-func NSUIMainScreen() -> NSUIScreen?
+#endif
+
+extension NSUIScreen
 {
-    return NSUIScreen.main
+    class var nsuiMain: NSUIScreen? { .main }
 }
-
-#endif