diff --git a/src/PhpSpreadsheet/Writer/Html.php b/src/PhpSpreadsheet/Writer/Html.php
index 629e3c0c..555f4dc7 100644
--- a/src/PhpSpreadsheet/Writer/Html.php
+++ b/src/PhpSpreadsheet/Writer/Html.php
@@ -477,12 +477,8 @@ class Html extends BaseWriter
                     $column = $minCol;
                     while ($column <= $maxCol) {
                         // Cell exists?
-                        if ($sheet->cellExistsByColumnAndRow($column, $row)) {
-                            $rowData[$column] = Coordinate::stringFromColumnIndex($column) . $row;
-                        } else {
-                            $rowData[$column] = '';
-                        }
-                        ++$column;
+                        $cellAddress = Coordinate::stringFromColumnIndex($column) . $row;
+                        $rowData[$column++] = ($sheet->getCellCollection()->has($cellAddress)) ? $cellAddress : '';
                     }
                     $html .= $this->generateRow($sheet, $rowData, $row - 1, $cellType);
                 }
@@ -1232,7 +1228,7 @@ class Html extends BaseWriter
 
     private function generateRowCellCss(Worksheet $worksheet, $cellAddress, $row, $columnNumber)
     {
-        $cell = ($cellAddress > '') ? $worksheet->getCell($cellAddress) : '';
+        $cell = ($cellAddress > '') ? $worksheet->getCellCollection()->get($cellAddress) : '';
         $coordinate = Coordinate::stringFromColumnIndex($columnNumber + 1) . ($row + 1);
         if (!$this->useInlineCss) {
             $cssClass = 'column' . $columnNumber;
diff --git a/src/PhpSpreadsheet/Writer/Ods/Content.php b/src/PhpSpreadsheet/Writer/Ods/Content.php
index 5d227c84..7e02fc51 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Content.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Content.php
@@ -8,6 +8,7 @@ use PhpOffice\PhpSpreadsheet\Cell\DataType;
 use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\Row;
+use PhpOffice\PhpSpreadsheet\Worksheet\RowCellIterator;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Writer\Exception;
 use PhpOffice\PhpSpreadsheet\Writer\Ods;
@@ -146,10 +147,10 @@ class Content extends WriterPart
         $numberRowsRepeated = self::NUMBER_ROWS_REPEATED_MAX;
         $span_row = 0;
         $rows = $sheet->getRowIterator();
-        while ($rows->valid()) {
+        foreach ($rows as $row) {
+            $cellIterator = $row->getCellIterator();
             --$numberRowsRepeated;
-            $row = $rows->current();
-            if ($row->getCellIterator()->valid()) {
+            if ($cellIterator->valid()) {
                 if ($span_row) {
                     $objWriter->startElement('table:table-row');
                     if ($span_row > 1) {
@@ -168,26 +169,23 @@ class Content extends WriterPart
                     $span_row = 0;
                 }
                 $objWriter->startElement('table:table-row');
-                $this->writeCells($objWriter, $row);
+                $this->writeCells($objWriter, $cellIterator);
                 $objWriter->endElement();
             } else {
                 ++$span_row;
             }
-            $rows->next();
         }
     }
 
     /**
      * Write cells of the specified row.
      */
-    private function writeCells(XMLWriter $objWriter, Row $row): void
+    private function writeCells(XMLWriter $objWriter, RowCellIterator $cells): void
     {
         $numberColsRepeated = self::NUMBER_COLS_REPEATED_MAX;
         $prevColumn = -1;
-        $cells = $row->getCellIterator();
-        while ($cells->valid()) {
+        foreach ($cells as $cell) {
             /** @var \PhpOffice\PhpSpreadsheet\Cell\Cell $cell */
-            $cell = $cells->current();
             $column = Coordinate::columnIndexFromString($cell->getColumn()) - 1;
 
             $this->writeCellSpan($objWriter, $column, $prevColumn);
@@ -250,8 +248,8 @@ class Content extends WriterPart
             Comment::write($objWriter, $cell);
             $objWriter->endElement();
             $prevColumn = $column;
-            $cells->next();
         }
+
         $numberColsRepeated = $numberColsRepeated - $prevColumn - 1;
         if ($numberColsRepeated > 0) {
             if ($numberColsRepeated > 1) {