diff --git a/chartLib/src/main/kotlin/info/appdev/charting/buffer/BarBuffer.kt b/chartLib/src/main/kotlin/info/appdev/charting/buffer/BarBuffer.kt
index 2dc36a57c..8ab727f89 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/buffer/BarBuffer.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/buffer/BarBuffer.kt
@@ -3,7 +3,7 @@ package info.appdev.charting.buffer
 import info.appdev.charting.interfaces.datasets.IBarDataSet
 import kotlin.math.abs
 
-open class BarBuffer(size: Int, dataSetCount: Int, containsStacks: Boolean) : AbstractBuffer<IBarDataSet?>(size) {
+open class BarBuffer(size: Int, dataSetCount: Int, containsStacks: Boolean) : AbstractBuffer<IBarDataSet>(size) {
     protected var dataSetIndex: Int = 0
     protected var dataSetCount: Int = 1
 
@@ -42,13 +42,13 @@ open class BarBuffer(size: Int, dataSetCount: Int, containsStacks: Boolean) : Ab
                 '}'
     }
 
-    override fun feed(data: IBarDataSet?) {
-        val size = (data?.entryCount ?: 0) * phaseX
+    override fun feed(data: IBarDataSet) {
+        val size = data.entryCount * phaseX
         val barWidthHalf = barWidth / 2f
 
         var i = 0
         while (i < size) {
-            val e = data?.getEntryForIndex(i)
+            val e = data.getEntryForIndex(i)
 
             if (e == null) {
                 i++
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/buffer/HorizontalBarBuffer.kt b/chartLib/src/main/kotlin/info/appdev/charting/buffer/HorizontalBarBuffer.kt
index 2c88f06ae..00f00837d 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/buffer/HorizontalBarBuffer.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/buffer/HorizontalBarBuffer.kt
@@ -4,13 +4,13 @@ import info.appdev.charting.interfaces.datasets.IBarDataSet
 import kotlin.math.abs
 
 class HorizontalBarBuffer(size: Int, dataSetCount: Int, containsStacks: Boolean) : BarBuffer(size, dataSetCount, containsStacks) {
-    override fun feed(data: IBarDataSet?) {
-        val size = (data?.entryCount ?: 0) * phaseX
+    override fun feed(data: IBarDataSet) {
+        val size = data.entryCount * phaseX
         val barWidthHalf = barWidth / 2f
 
         var i = 0
         while (i < size) {
-            val e = data?.getEntryForIndex(i)
+            val e = data.getEntryForIndex(i)
 
             if (e == null) {
                 i++
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/charts/Chart.kt b/chartLib/src/main/kotlin/info/appdev/charting/charts/Chart.kt
index b7adcde40..af699efcb 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/charts/Chart.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/charts/Chart.kt
@@ -49,7 +49,7 @@ import kotlin.math.abs
 import kotlin.math.max
 
 @Suppress("unused")
-abstract class Chart<T : ChartData<out IDataSet<out Entry>>?> : ViewGroup, IBaseProvider {
+abstract class Chart<T : ChartData<out IDataSet<out Entry>>> : ViewGroup, IBaseProvider {
     /**
      * Returns true if log-output is enabled for the chart, fals if not.
      */
@@ -1167,7 +1167,7 @@ abstract class Chart<T : ChartData<out IDataSet<out Entry>>?> : ViewGroup, IBase
     /**
      * tasks to be done after the view is setup
      */
-    var jobs: ArrayList<Runnable?> = ArrayList()
+    var jobs: ArrayList<Runnable> = ArrayList()
         protected set
 
     fun removeViewportJob(job: Runnable?) {
@@ -1182,7 +1182,7 @@ abstract class Chart<T : ChartData<out IDataSet<out Entry>>?> : ViewGroup, IBase
      * Either posts a job immediately if the chart has already setup it's
      * dimensions or adds the job to the execution queue.
      */
-    fun addViewportJob(job: Runnable?) {
+    fun addViewportJob(job: Runnable) {
         if (viewPortHandler.hasChartDimens()) {
             post(job)
         } else {
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/components/Legend.kt b/chartLib/src/main/kotlin/info/appdev/charting/components/Legend.kt
index 34f380b59..7c876ecbb 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/components/Legend.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/components/Legend.kt
@@ -332,9 +332,9 @@ class Legend() : ComponentBase() {
      */
     var isWordWrapEnabled: Boolean = false
 
-    val calculatedLabelSizes: MutableList<FSize?> = ArrayList<FSize?>(16)
-    val calculatedLabelBreakPoints: MutableList<Boolean?> = ArrayList<Boolean?>(16)
-    val calculatedLineSizes: MutableList<FSize?> = ArrayList<FSize?>(16)
+    val calculatedLabelSizes: MutableList<FSize> = ArrayList(16)
+    val calculatedLabelBreakPoints: MutableList<Boolean> = ArrayList(16)
+    val calculatedLineSizes: MutableList<FSize> = ArrayList(16)
 
     init {
         this.mTextSize = 10f.convertDpToPixel()
@@ -454,7 +454,7 @@ class Legend() : ComponentBase() {
                     if (label != null) {
                         calculatedLabelSizes.add(labelpaint.calcTextSize(label))
                         requiredWidth += if (drawingForm) formToTextSpace + formSize else 0f
-                        requiredWidth += calculatedLabelSizes.get(i)!!.width
+                        requiredWidth += calculatedLabelSizes.get(i).width
                     } else {
                         calculatedLabelSizes.add(FSize.getInstance(0f, 0f))
                         requiredWidth += if (drawingForm) formSize else 0f
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/Entry.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/Entry.kt
index dd33743e2..b285d89dc 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/Entry.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/Entry.kt
@@ -132,7 +132,7 @@ open class Entry : BaseEntry, Parcelable, Serializable {
 
     companion object {
         @JvmField
-        val CREATOR: Parcelable.Creator<Entry?> = object : Parcelable.Creator<Entry?> {
+        val CREATOR: Parcelable.Creator<Entry> = object : Parcelable.Creator<Entry> {
             override fun createFromParcel(source: Parcel): Entry {
                 return Entry(source)
             }
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/RadarData.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/RadarData.kt
index e6b1fc1d8..d3a9d37ed 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/RadarData.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/RadarData.kt
@@ -2,7 +2,6 @@ package info.appdev.charting.data
 
 import info.appdev.charting.highlight.Highlight
 import info.appdev.charting.interfaces.datasets.IRadarDataSet
-import java.util.Arrays
 
 /**
  * Data container for the RadarChart.
@@ -13,7 +12,7 @@ class RadarData : ChartData<IRadarDataSet> {
      *
      * @param labels
      */
-    var labels: MutableList<String?>? = null
+    var labels: MutableList<String>? = null
 
     constructor() : super()
 
@@ -23,11 +22,9 @@ class RadarData : ChartData<IRadarDataSet> {
 
     /**
      * Sets the labels that should be drawn around the RadarChart at the end of each web line.
-     *
-     * @param labels
      */
-    fun setLabels(vararg labels: String?) {
-        this.labels = Arrays.asList<String?>(*labels)
+    fun setLabels(vararg labels: String) {
+        this.labels = mutableListOf(*labels)
     }
 
     override fun getEntryForHighlight(highlight: Highlight): Entry? {
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/renderer/LegendRenderer.kt b/chartLib/src/main/kotlin/info/appdev/charting/renderer/LegendRenderer.kt
index f015af03c..408f57dbb 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/renderer/LegendRenderer.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/renderer/LegendRenderer.kt
@@ -297,13 +297,13 @@ open class LegendRenderer(
                     else
                         entry.formSize.convertDpToPixel()
 
-                    if (i < calculatedLabelBreakPoints.size && calculatedLabelBreakPoints[i] == true) {
+                    if (i < calculatedLabelBreakPoints.size && calculatedLabelBreakPoints[i]) {
                         posX = originPosX
                         posY += labelLineHeight + labelLineSpacing
                     }
 
                     if (posX == originPosX && horizontalAlignment == LegendHorizontalAlignment.CENTER && lineIndex < calculatedLineSizes.size) {
-                        calculatedLineSizes[lineIndex]?.let { fSize ->
+                        calculatedLineSizes[lineIndex].let { fSize ->
                             posX += (if (direction == LegendDirection.RIGHT_TO_LEFT)
                                 fSize.width
                             else
@@ -326,12 +326,12 @@ open class LegendRenderer(
                         if (drawingForm) posX += if (direction == LegendDirection.RIGHT_TO_LEFT) -formToTextSpace else formToTextSpace
 
                         if (direction == LegendDirection.RIGHT_TO_LEFT)
-                            posX -= calculatedLabelSizes[i]?.width ?: 0f
+                            posX -= calculatedLabelSizes[i].width
 
                         drawLabel(canvas, posX, posY + labelLineHeight, entry.label)
 
                         if (direction == LegendDirection.LEFT_TO_RIGHT)
-                            posX += calculatedLabelSizes[i]?.width ?: 0f
+                            posX += calculatedLabelSizes[i].width
 
                         posX += if (direction == LegendDirection.RIGHT_TO_LEFT) -xEntrySpace else xEntrySpace
                     } else posX += if (direction == LegendDirection.RIGHT_TO_LEFT) -stackSpace else stackSpace