diff --git a/docs/changes/1.0.0.md b/docs/changes/1.0.0.md
index aea01fef3..230992c33 100644
--- a/docs/changes/1.0.0.md
+++ b/docs/changes/1.0.0.md
@@ -40,6 +40,9 @@
 - Support for rotation for axis label - @Progi1986 GH-410
   - ODPresentation Writer
   - PowerPoint2007 Writer
+- Support for managing missing values in Chart - @TonisOrmisson GH-581 & @Progi1986 GH-659
+  - ODPresentation Writer
+  - PowerPoint2007 Writer
 
 ## Project Management
 - Migrated from Travis CI to Github Actions - @Progi1984 GH-635
diff --git a/docs/images/libreoffice_chart_displayblankas.png b/docs/images/libreoffice_chart_displayblankas.png
new file mode 100644
index 000000000..c37331d77
Binary files /dev/null and b/docs/images/libreoffice_chart_displayblankas.png differ
diff --git a/docs/usage/presentation.md b/docs/usage/presentation.md
index 2680474c1..7e34e4684 100644
--- a/docs/usage/presentation.md
+++ b/docs/usage/presentation.md
@@ -138,7 +138,7 @@ $state = $presentation->isMarkedAsFinal();
 
 You can define the type of slideshow you can with the method `setSlideshowType`.
 
-![Slideshow type](/PHPPresentation/images/presentation_slideshow_type.png)
+![Slideshow type](/images/presentation_slideshow_type.png)
 
 Differents types are available:
 
diff --git a/docs/usage/shapes/chart.md b/docs/usage/shapes/chart.md
index ace7e3f12..0e6c8b315 100644
--- a/docs/usage/shapes/chart.md
+++ b/docs/usage/shapes/chart.md
@@ -8,6 +8,31 @@ To create a chart, use `createChartShape` method of Slide.
 $chartShape = $slide->createChartShape();
 ```
 
+## Customization
+
+### Manage how blank values are displayed
+
+You can define how blank values are displayed with the method `setDisplayBlankAs`.
+
+![Slideshow type](/images/libreoffice_chart_displayblankas.png)
+
+Differents types are available:
+
+* `Chart::BLANKAS_GAP` for **Leave a gap**
+* `Chart::BLANKAS_ZERO` for **Assume zero** (default)
+* `Chart::BLANKAS_SPAN` for **Continue line**
+
+``` php
+<?php
+
+use PhpOffice\PhpPresentation\Shape\Chart;
+
+// Set the behavior
+$chart->setDisplayBlankAs(Chart::BLANKAS_GAP);
+// Get the behavior
+echo $chart->getDisplayBlankAs();
+```
+
 ## Parts
 
 ### Axis
diff --git a/samples/Sample_05_Chart_Line.php b/samples/Sample_05_Chart_Line.php
index 84b232b64..c0c59ef44 100644
--- a/samples/Sample_05_Chart_Line.php
+++ b/samples/Sample_05_Chart_Line.php
@@ -3,11 +3,15 @@
 include_once 'Sample_Header.php';
 
 use PhpOffice\PhpPresentation\PhpPresentation;
+use PhpOffice\PhpPresentation\Shape\Chart;
+use PhpOffice\PhpPresentation\Shape\Chart\Gridlines;
+use PhpOffice\PhpPresentation\Shape\Chart\Marker;
 use PhpOffice\PhpPresentation\Shape\Chart\Series;
 use PhpOffice\PhpPresentation\Shape\Chart\Type\Line;
 use PhpOffice\PhpPresentation\Style\Border;
 use PhpOffice\PhpPresentation\Style\Color;
 use PhpOffice\PhpPresentation\Style\Fill;
+use PhpOffice\PhpPresentation\Style\Outline;
 use PhpOffice\PhpPresentation\Style\Shadow;
 
 // Create new PHPPresentation object
@@ -73,7 +77,7 @@
 $currentSlide = createTemplatedSlide($objPHPPresentation);
 
 // Create a line chart (that should be inserted in a shape)
-$oOutline = new \PhpOffice\PhpPresentation\Style\Outline();
+$oOutline = new Outline();
 $oOutline->getFill()->setFillType(Fill::FILL_SOLID);
 $oOutline->getFill()->setStartColor(new Color(Color::COLOR_YELLOW));
 $oOutline->setWidth(2);
@@ -82,7 +86,7 @@
 $lineChart1 = clone $lineChart;
 $series1 = $lineChart1->getSeries();
 $series1[0]->setOutline($oOutline);
-$series1[0]->getMarker()->setSymbol(\PhpOffice\PhpPresentation\Shape\Chart\Marker::SYMBOL_DIAMOND);
+$series1[0]->getMarker()->setSymbol(Marker::SYMBOL_DIAMOND);
 $series1[0]->getMarker()->setSize(7);
 $lineChart1->setSeries($series1);
 
@@ -106,7 +110,7 @@
 $lineChart2 = clone $lineChart;
 $series2 = $lineChart2->getSeries();
 $series2[0]->getFont()->setSize(25);
-$series2[0]->getMarker()->setSymbol(\PhpOffice\PhpPresentation\Shape\Chart\Marker::SYMBOL_TRIANGLE);
+$series2[0]->getMarker()->setSymbol(Marker::SYMBOL_TRIANGLE);
 $series2[0]->getMarker()->setSize(10);
 $lineChart2->setSeries($series2);
 
@@ -129,11 +133,11 @@
 echo date('H:i:s') . ' Create a line chart (that should be inserted in a chart shape)' . EOL;
 $lineChart3 = clone $lineChart;
 
-$oGridLines1 = new \PhpOffice\PhpPresentation\Shape\Chart\Gridlines();
+$oGridLines1 = new Gridlines();
 $oGridLines1->getOutline()->setWidth(10);
 $oGridLines1->getOutline()->getFill()->setFillType(Fill::FILL_SOLID)->setStartColor(new Color(Color::COLOR_BLUE));
 
-$oGridLines2 = new \PhpOffice\PhpPresentation\Shape\Chart\Gridlines();
+$oGridLines2 = new Gridlines();
 $oGridLines2->getOutline()->setWidth(1);
 $oGridLines2->getOutline()->getFill()->setFillType(Fill::FILL_SOLID)->setStartColor(new Color(Color::COLOR_DARKGREEN));
 
@@ -156,12 +160,12 @@
 echo date('H:i:s') . ' Create a line chart (that should be inserted in a chart shape)' . EOL;
 $lineChart4 = clone $lineChart;
 
-$oOutlineAxisX = new \PhpOffice\PhpPresentation\Style\Outline();
+$oOutlineAxisX = new Outline();
 $oOutlineAxisX->setWidth(2);
 $oOutlineAxisX->getFill()->setFillType(Fill::FILL_SOLID);
 $oOutlineAxisX->getFill()->getStartColor()->setRGB('012345');
 
-$oOutlineAxisY = new \PhpOffice\PhpPresentation\Style\Outline();
+$oOutlineAxisY = new Outline();
 $oOutlineAxisY->setWidth(5);
 $oOutlineAxisY->getFill()->setFillType(Fill::FILL_SOLID);
 $oOutlineAxisY->getFill()->getStartColor()->setRGB('ABCDEF');
@@ -190,6 +194,26 @@
 $shape5->getPlotArea()->getAxisY()->setMinBounds(5);
 $shape5->getPlotArea()->getAxisY()->setMaxBounds(20);
 $currentSlide->addShape($shape5);
+
+// Create templated slide
+echo EOL . date('H:i:s') . ' Create templated slide #6' . EOL;
+$currentSlide = createTemplatedSlide($objPHPPresentation);
+
+// Create a shape (chart)
+echo date('H:i:s') . ' Create a shape (chart6)' . EOL;
+echo date('H:i:s') . ' Feature : DisplayBlankAs' . EOL;
+$shape6 = clone $shape;
+$lineChart6 = clone $lineChart;
+$series6 = clone $series;
+$seriesData6 = $seriesData;
+$seriesData6['Thursday'] = null;
+
+$series6->setValues($seriesData6);
+$lineChart6->setSeries([$series6]);
+$shape6->getPlotArea()->setType($lineChart6);
+$shape6->setDisplayBlankAs(Chart::BLANKAS_GAP);
+$currentSlide->addShape($shape6);
+
 // Save file
 echo EOL . write($objPHPPresentation, basename(__FILE__, '.php'), $writers);
 
diff --git a/src/PhpPresentation/Shape/Chart.php b/src/PhpPresentation/Shape/Chart.php
index d840ccb3b..7cebcb3b2 100644
--- a/src/PhpPresentation/Shape/Chart.php
+++ b/src/PhpPresentation/Shape/Chart.php
@@ -29,6 +29,10 @@
  */
 class Chart extends AbstractGraphic implements ComparableInterface
 {
+    public const BLANKAS_GAP = 'gap';
+    public const BLANKAS_ZERO = 'zero';
+    public const BLANKAS_SPAN = 'span';
+
     /**
      * Title.
      *
@@ -64,6 +68,13 @@ class Chart extends AbstractGraphic implements ComparableInterface
      */
     private $includeSpreadsheet = false;
 
+    /**
+     * How to display blank (missing) values? Not set by default.
+     *
+     * @var string
+     */
+    private $displayBlankAs = self::BLANKAS_ZERO;
+
     /**
      * Create a new Chart.
      */
@@ -89,6 +100,16 @@ public function __clone()
         $this->view3D = clone $this->view3D;
     }
 
+    /**
+     * How missing/blank values are displayed on chart (dispBlanksAs property)
+     *
+     * @return string
+     */
+    public function getDisplayBlankAs(): string
+    {
+        return $this->displayBlankAs;
+    }
+
     /**
      * Get Title.
      *
@@ -139,6 +160,22 @@ public function hasIncludedSpreadsheet(): bool
         return $this->includeSpreadsheet;
     }
 
+    /**
+     * Define a way to display missing/blank values (dispBlanksAs property)
+     *
+     * @param string $value
+     *
+     * @return self
+     */
+    public function setDisplayBlankAs(string $value): self
+    {
+        if (in_array($value, [self::BLANKAS_GAP, self::BLANKAS_SPAN, self::BLANKAS_ZERO])) {
+            $this->displayBlankAs = $value;
+        }
+
+        return $this;
+    }
+
     /**
      * Is the spreadsheet included for editing data ?
      *
diff --git a/src/PhpPresentation/Shape/Chart/Series.php b/src/PhpPresentation/Shape/Chart/Series.php
index 15616fa2d..b60d03f24 100644
--- a/src/PhpPresentation/Shape/Chart/Series.php
+++ b/src/PhpPresentation/Shape/Chart/Series.php
@@ -132,7 +132,7 @@ class Series implements ComparableInterface
     /**
      * Values (key/value).
      *
-     * @var array<string, string>
+     * @var array<string, string|null>
      */
     private $values = [];
 
@@ -144,7 +144,8 @@ class Series implements ComparableInterface
     private $hashIndex;
 
     /**
-     * @param array<string, string> $values
+     * @param string $title
+     * @param array<string, string|null> $values
      */
     public function __construct(string $title = 'Series Title', array $values = [])
     {
@@ -152,9 +153,10 @@ public function __construct(string $title = 'Series Title', array $values = [])
         $this->font = new Font();
         $this->font->setName('Calibri');
         $this->font->setSize(9);
+        $this->marker = new Marker();
+
         $this->title = $title;
         $this->values = $values;
-        $this->marker = new Marker();
     }
 
     /**
@@ -239,7 +241,7 @@ public function getDataPointFills(): array
     /**
      * Get Values.
      *
-     * @return array<string, string>
+     * @return array<string, string|null>
      */
     public function getValues(): array
     {
@@ -249,7 +251,7 @@ public function getValues(): array
     /**
      * Set Values.
      *
-     * @param array<string, string> $values
+     * @param array<string, string|null> $values
      */
     public function setValues(array $values = []): self
     {
@@ -260,8 +262,13 @@ public function setValues(array $values = []): self
 
     /**
      * Add Value.
+     *
+     * @param string $key
+     * @param string|null $value
+     *
+     * @return self
      */
-    public function addValue(string $key, string $value): self
+    public function addValue(string $key, ?string $value): self
     {
         $this->values[$key] = $value;
 
diff --git a/src/PhpPresentation/Writer/ODPresentation/ObjectsChart.php b/src/PhpPresentation/Writer/ODPresentation/ObjectsChart.php
index ce2473c08..fc53d0e23 100644
--- a/src/PhpPresentation/Writer/ODPresentation/ObjectsChart.php
+++ b/src/PhpPresentation/Writer/ODPresentation/ObjectsChart.php
@@ -544,6 +544,17 @@ private function writePlotAreaStyle(Chart $chart): void
             $this->xmlContent->writeAttribute('chart:three-dimensional', 'true');
             $this->xmlContent->writeAttribute('chart:right-angled-axes', 'true');
         }
+        switch ($chart->getDisplayBlankAs()) {
+            case Chart::BLANKAS_ZERO:
+                $this->xmlContent->writeAttribute('chart:treat-empty-cells', 'use-zero');
+                break;
+            case Chart::BLANKAS_GAP:
+                $this->xmlContent->writeAttribute('chart:treat-empty-cells', 'leave-gap');
+                break;
+            case Chart::BLANKAS_SPAN:
+                $this->xmlContent->writeAttribute('chart:treat-empty-cells', 'ignore');
+                break;
+        }
         if ($chartType instanceof AbstractTypeBar) {
             $chartVertical = 'false';
             if (AbstractTypeBar::DIRECTION_HORIZONTAL == $chartType->getBarDirection()) {
@@ -809,40 +820,6 @@ private function writeTable(): void
         // > table:table-header-columns
         $this->xmlContent->endElement();
 
-        // table:table-rows
-        $this->xmlContent->startElement('table:table-rows');
-        if (empty($this->arrayData)) {
-            $this->xmlContent->startElement('table:table-row');
-            $this->xmlContent->startElement('table:table-cell');
-            $this->xmlContent->endElement();
-            $this->xmlContent->endElement();
-        } else {
-            foreach ($this->arrayData as $row) {
-                // table:table-row
-                $this->xmlContent->startElement('table:table-row');
-                foreach ($row as $cell) {
-                    // table:table-cell
-                    $this->xmlContent->startElement('table:table-cell');
-
-                    $cellNumeric = is_numeric($cell);
-                    $this->xmlContent->writeAttributeIf(!$cellNumeric, 'office:value-type', 'string');
-                    $this->xmlContent->writeAttributeIf($cellNumeric, 'office:value-type', 'float');
-                    $this->xmlContent->writeAttributeIf($cellNumeric, 'office:value', $cell);
-                    // text:p
-                    $this->xmlContent->startElement('text:p');
-                    $this->xmlContent->text($cell);
-                    // > text:p
-                    $this->xmlContent->endElement();
-                    // > table:table-cell
-                    $this->xmlContent->endElement();
-                }
-                // > table:table-row
-                $this->xmlContent->endElement();
-            }
-        }
-        // > table:table-rows
-        $this->xmlContent->endElement();
-
         // table:table-header-rows
         $this->xmlContent->startElement('table:table-header-rows');
         // table:table-row
@@ -874,6 +851,39 @@ private function writeTable(): void
         // > table:table-header-rows
         $this->xmlContent->endElement();
 
+        // table:table-rows
+        $this->xmlContent->startElement('table:table-rows');
+        if (empty($this->arrayData)) {
+            $this->xmlContent->startElement('table:table-row');
+            $this->xmlContent->startElement('table:table-cell');
+            $this->xmlContent->endElement();
+            $this->xmlContent->endElement();
+        } else {
+            foreach ($this->arrayData as $row) {
+                // table:table-row
+                $this->xmlContent->startElement('table:table-row');
+                foreach ($row as $cell) {
+                    // table:table-cell
+                    $this->xmlContent->startElement('table:table-cell');
+
+                    $cellValueTypeFloat = is_null($cell) ? true : is_numeric($cell);
+                    $this->xmlContent->writeAttributeIf(!$cellValueTypeFloat, 'office:value-type', 'string');
+                    $this->xmlContent->writeAttributeIf($cellValueTypeFloat, 'office:value-type', 'float');
+                    $this->xmlContent->writeAttributeIf($cellValueTypeFloat, 'office:value', is_null($cell) ? 'NaN' : $cell);
+                    // text:p
+                    $this->xmlContent->startElement('text:p');
+                    $this->xmlContent->text(is_null($cell) ? 'NaN' : $cell);
+                    $this->xmlContent->endElement();
+                    // > table:table-cell
+                    $this->xmlContent->endElement();
+                }
+                // > table:table-row
+                $this->xmlContent->endElement();
+            }
+        }
+        // > table:table-rows
+        $this->xmlContent->endElement();
+
         // > table:table
         $this->xmlContent->endElement();
     }
diff --git a/src/PhpPresentation/Writer/PowerPoint2007/PptCharts.php b/src/PhpPresentation/Writer/PowerPoint2007/PptCharts.php
index a90b16ade..a031d0bc6 100644
--- a/src/PhpPresentation/Writer/PowerPoint2007/PptCharts.php
+++ b/src/PhpPresentation/Writer/PowerPoint2007/PptCharts.php
@@ -146,6 +146,11 @@ public function writeChart(Chart $chart): string
         $objWriter->writeAttribute('val', '1');
         $objWriter->endElement();
 
+        // c:dispBlanksAs
+        $objWriter->startElement('c:dispBlanksAs');
+        $objWriter->writeAttribute('val', $chart->getDisplayBlankAs());
+        $objWriter->endElement();
+
         $objWriter->endElement();
 
         // c:spPr
diff --git a/tests/PhpPresentation/Tests/Shape/ChartTest.php b/tests/PhpPresentation/Tests/Shape/ChartTest.php
index 0195aa19f..a042fa8df 100644
--- a/tests/PhpPresentation/Tests/Shape/ChartTest.php
+++ b/tests/PhpPresentation/Tests/Shape/ChartTest.php
@@ -32,10 +32,10 @@ public function testConstruct(): void
     {
         $object = new Chart();
 
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\Title', $object->getTitle());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\Legend', $object->getLegend());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\PlotArea', $object->getPlotArea());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\View3D', $object->getView3D());
+        $this->assertInstanceOf(Chart\Title::class, $object->getTitle());
+        $this->assertInstanceOf(Chart\Legend::class, $object->getLegend());
+        $this->assertInstanceOf(Chart\PlotArea::class, $object->getPlotArea());
+        $this->assertInstanceOf(Chart\View3D::class, $object->getView3D());
     }
 
     public function testClone(): void
@@ -44,11 +44,26 @@ public function testClone(): void
 
         $oClone = clone $object;
 
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart', $oClone);
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\Title', $oClone->getTitle());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\Legend', $oClone->getLegend());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\PlotArea', $oClone->getPlotArea());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart\\View3D', $oClone->getView3D());
+        $this->assertInstanceOf(Chart::class, $oClone);
+        $this->assertInstanceOf(Chart\Title::class, $oClone->getTitle());
+        $this->assertInstanceOf(Chart\Legend::class, $oClone->getLegend());
+        $this->assertInstanceOf(Chart\PlotArea::class, $oClone->getPlotArea());
+        $this->assertInstanceOf(Chart\View3D::class, $oClone->getView3D());
+    }
+
+    public function testDisplayBlankAs(): void
+    {
+        $object = new Chart();
+
+        $this->assertEquals(Chart::BLANKAS_ZERO, $object->getDisplayBlankAs());
+        $this->assertInstanceOf(Chart::class, $object->setDisplayBlankAs(Chart::BLANKAS_GAP));
+        $this->assertEquals(Chart::BLANKAS_GAP, $object->getDisplayBlankAs());
+        $this->assertInstanceOf(Chart::class, $object->setDisplayBlankAs(Chart::BLANKAS_ZERO));
+        $this->assertEquals(Chart::BLANKAS_ZERO, $object->getDisplayBlankAs());
+        $this->assertInstanceOf(Chart::class, $object->setDisplayBlankAs(Chart::BLANKAS_SPAN));
+        $this->assertEquals(Chart::BLANKAS_SPAN, $object->getDisplayBlankAs());
+        $this->assertInstanceOf(Chart::class, $object->setDisplayBlankAs('Unauthorized value'));
+        $this->assertEquals(Chart::BLANKAS_SPAN, $object->getDisplayBlankAs());
     }
 
     public function testIncludeSpreadsheet(): void
@@ -56,11 +71,11 @@ public function testIncludeSpreadsheet(): void
         $object = new Chart();
 
         $this->assertFalse($object->hasIncludedSpreadsheet());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart', $object->setIncludeSpreadsheet());
+        $this->assertInstanceOf(Chart::class, $object->setIncludeSpreadsheet());
         $this->assertFalse($object->hasIncludedSpreadsheet());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart', $object->setIncludeSpreadsheet(false));
+        $this->assertInstanceOf(Chart::class, $object->setIncludeSpreadsheet(false));
         $this->assertFalse($object->hasIncludedSpreadsheet());
-        $this->assertInstanceOf('PhpOffice\\PhpPresentation\\Shape\\Chart', $object->setIncludeSpreadsheet(true));
+        $this->assertInstanceOf(Chart::class, $object->setIncludeSpreadsheet(true));
         $this->assertTrue($object->hasIncludedSpreadsheet());
     }
 }
diff --git a/tests/PhpPresentation/Tests/Writer/ODPresentation/ObjectsChartTest.php b/tests/PhpPresentation/Tests/Writer/ODPresentation/ObjectsChartTest.php
index 3ca0b8c0d..89b149341 100644
--- a/tests/PhpPresentation/Tests/Writer/ODPresentation/ObjectsChartTest.php
+++ b/tests/PhpPresentation/Tests/Writer/ODPresentation/ObjectsChartTest.php
@@ -3,6 +3,7 @@
 namespace PhpOffice\PhpPresentation\Tests\Writer\ODPresentation;
 
 use PhpOffice\Common\Drawing as CommonDrawing;
+use PhpOffice\PhpPresentation\Shape\Chart;
 use PhpOffice\PhpPresentation\Shape\Chart\Gridlines;
 use PhpOffice\PhpPresentation\Shape\Chart\Legend;
 use PhpOffice\PhpPresentation\Shape\Chart\Marker;
@@ -166,6 +167,46 @@ public function testAxisVisibility(): void
         $this->assertIsSchemaOpenDocumentNotValid('1.2');
     }
 
+    public function testChartDisplayBlankAs(): void
+    {
+        $oSeries = new Series('Downloads', $this->seriesData);
+
+        $oLine = new Line();
+        $oLine->addSeries($oSeries);
+
+        $oShape = $this->oPresentation->getActiveSlide()->createChartShape();
+        $oShape->getPlotArea()->setType($oLine);
+        $oShape->setDisplayBlankAs(Chart::BLANKAS_ZERO);
+
+        $element = '/office:document-content/office:automatic-styles/style:style[@style:name=\'stylePlotArea\']/style:chart-properties';
+        $this->assertZipFileExists('Object 1/content.xml');
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'chart:treat-empty-cells');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'chart:treat-empty-cells', 'use-zero');
+        // chart:title : Element chart failed to validate attributes
+        $this->assertIsSchemaOpenDocumentNotValid('1.2');
+
+        $this->resetPresentationFile();
+        $oShape->setDisplayBlankAs(Chart::BLANKAS_SPAN);
+
+        $this->assertZipFileExists('Object 1/content.xml');
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'chart:treat-empty-cells');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'chart:treat-empty-cells', 'ignore');
+        // chart:title : Element chart failed to validate attributes
+        $this->assertIsSchemaOpenDocumentNotValid('1.2');
+
+        $this->resetPresentationFile();
+        $oShape->setDisplayBlankAs(Chart::BLANKAS_GAP);
+
+        $this->assertZipFileExists('Object 1/content.xml');
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'chart:treat-empty-cells');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'chart:treat-empty-cells', 'leave-gap');
+        // chart:title : Element chart failed to validate attributes
+        $this->assertIsSchemaOpenDocumentNotValid('1.2');
+    }
+
     public function testLegend(): void
     {
         $oSeries = new Series('Series', ['Jan' => '1', 'Feb' => '5', 'Mar' => '2']);
@@ -238,7 +279,72 @@ public function testLegend(): void
         $this->assertIsSchemaOpenDocumentNotValid('1.2');
     }
 
-    public function testSeries(): void
+    public function testSeriesValues(): void
+    {
+        $series = new Series('Series', ['Jan' => null]);
+
+        $pie = new Pie();
+        $pie->addSeries($series);
+
+        $chart = $this->oPresentation->getActiveSlide()->createChartShape();
+        $chart->getPlotArea()->setType($pie);
+
+        $element = '/office:document-content/office:body/office:chart/chart:chart/table:table/table:table-rows/table:table-row/table:table-cell[2]';
+
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'office:value-type');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'office:value-type', 'float');
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'office:value');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'office:value', 'NaN');
+
+        $element = '/office:document-content/office:body/office:chart/chart:chart/table:table/table:table-rows/table:table-row/table:table-cell[2]/text:p';
+
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlElementEquals('Object 1/content.xml', $element, 'NaN');
+        // chart:title : Element chart failed to validate attributes
+        $this->assertIsSchemaOpenDocumentNotValid('1.2');
+
+        $this->resetPresentationFile();
+
+        $series = new Series('Series', ['Jan' => '12.3']);
+        $chart->getPlotArea()->getType()->setSeries([$series]);
+
+        $element = '/office:document-content/office:body/office:chart/chart:chart/table:table/table:table-rows/table:table-row/table:table-cell[2]';
+
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'office:value-type');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'office:value-type', 'float');
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'office:value');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'office:value', '12.3');
+
+        $element = '/office:document-content/office:body/office:chart/chart:chart/table:table/table:table-rows/table:table-row/table:table-cell[2]/text:p';
+
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlElementEquals('Object 1/content.xml', $element, '12.3');
+        // chart:title : Element chart failed to validate attributes
+        $this->assertIsSchemaOpenDocumentNotValid('1.2');
+
+        $this->resetPresentationFile();
+
+        $series = new Series('Series', ['Jan' => 'data']);
+        $chart->getPlotArea()->getType()->setSeries([$series]);
+
+        $element = '/office:document-content/office:body/office:chart/chart:chart/table:table/table:table-rows/table:table-row/table:table-cell[2]';
+
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlAttributeExists('Object 1/content.xml', $element, 'office:value-type');
+        $this->assertZipXmlAttributeEquals('Object 1/content.xml', $element, 'office:value-type', 'string');
+        $this->assertZipXmlAttributeNotExists('Object 1/content.xml', $element, 'office:value');
+
+        $element = '/office:document-content/office:body/office:chart/chart:chart/table:table/table:table-rows/table:table-row/table:table-cell[2]/text:p';
+
+        $this->assertZipXmlElementExists('Object 1/content.xml', $element);
+        $this->assertZipXmlElementEquals('Object 1/content.xml', $element, 'data');
+        // chart:title : Element chart failed to validate attributes
+        $this->assertIsSchemaOpenDocumentNotValid('1.2');
+    }
+
+    public function testSeriesShowConfig(): void
     {
         $oSeries = new Series('Series', ['Jan' => '1', 'Feb' => '5', 'Mar' => '2']);
         $oPie = new Pie();
diff --git a/tests/PhpPresentation/Tests/Writer/PowerPoint2007/PptChartsTest.php b/tests/PhpPresentation/Tests/Writer/PowerPoint2007/PptChartsTest.php
index fbb794f3e..41de5a90d 100644
--- a/tests/PhpPresentation/Tests/Writer/PowerPoint2007/PptChartsTest.php
+++ b/tests/PhpPresentation/Tests/Writer/PowerPoint2007/PptChartsTest.php
@@ -4,6 +4,7 @@
 
 use Exception;
 use PhpOffice\Common\Drawing;
+use PhpOffice\PhpPresentation\Shape\Chart;
 use PhpOffice\PhpPresentation\Shape\Chart\Axis;
 use PhpOffice\PhpPresentation\Shape\Chart\Gridlines;
 use PhpOffice\PhpPresentation\Shape\Chart\Marker;
@@ -39,6 +40,47 @@ class PptChartsTest extends PhpPresentationTestCase
         'E' => '2',
     ];
 
+    public function testChartDisplayBlankAs(): void
+    {
+        $oSeries = new Series('Downloads', $this->seriesData);
+
+        $oLine = new Line();
+        $oLine->addSeries($oSeries);
+
+        $oShape = $this->oPresentation->getActiveSlide()->createChartShape();
+        $oShape->getPlotArea()->setType($oLine);
+        $oShape->setDisplayBlankAs(Chart::BLANKAS_ZERO);
+
+        $element = '/c:chartSpace/c:chart/c:dispBlanksAs';
+
+        $this->assertZipFileExists('ppt/charts/' . $oShape->getIndexedFilename());
+        $this->assertZipXmlElementExists('ppt/charts/' . $oShape->getIndexedFilename(), $element);
+        $this->assertZipXmlAttributeExists('ppt/charts/' . $oShape->getIndexedFilename(), $element, 'val');
+        $this->assertZipXmlAttributeEquals('ppt/charts/' . $oShape->getIndexedFilename(), $element, 'val', Chart::BLANKAS_ZERO);
+
+        $this->assertIsSchemaECMA376Valid();
+
+        $this->resetPresentationFile();
+        $oShape->setDisplayBlankAs(Chart::BLANKAS_SPAN);
+
+        $this->assertZipFileExists('ppt/charts/' . $oShape->getIndexedFilename());
+        $this->assertZipXmlElementExists('ppt/charts/' . $oShape->getIndexedFilename(), $element);
+        $this->assertZipXmlAttributeExists('ppt/charts/' . $oShape->getIndexedFilename(), $element, 'val');
+        $this->assertZipXmlAttributeEquals('ppt/charts/' . $oShape->getIndexedFilename(), $element, 'val', Chart::BLANKAS_SPAN);
+
+        $this->assertIsSchemaECMA376Valid();
+
+        $this->resetPresentationFile();
+        $oShape->setDisplayBlankAs(Chart::BLANKAS_GAP);
+
+        $this->assertZipFileExists('ppt/charts/' . $oShape->getIndexedFilename());
+        $this->assertZipXmlElementExists('ppt/charts/' . $oShape->getIndexedFilename(), $element);
+        $this->assertZipXmlAttributeExists('ppt/charts/' . $oShape->getIndexedFilename(), $element, 'val');
+        $this->assertZipXmlAttributeEquals('ppt/charts/' . $oShape->getIndexedFilename(), $element, 'val', Chart::BLANKAS_GAP);
+
+        $this->assertIsSchemaECMA376Valid();
+    }
+
     public function testChartIncludeSpreadsheet(): void
     {
         $oSlide = $this->oPresentation->getActiveSlide();