diff --git a/CHANGELOG.md b/CHANGELOG.md
index d3ce9b5b..1f08b073 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 - COUPNUM should not return zero when settlement is in the last period - [Issue #1020](https://github.com/PHPOffice/PhpSpreadsheet/issues/1020) and [PR #1021](https://github.com/PHPOffice/PhpSpreadsheet/pull/1021)
 - Fix handling of named ranges referencing sheets with spaces or "!" in their title
 - Cover `getSheetByName()` with tests for name with quote and spaces - [#739](https://github.com/PHPOffice/PhpSpreadsheet/issues/739)
+- Best effort to support invalid colspan values in HTML reader - [878](https://github.com/PHPOffice/PhpSpreadsheet/pull/878)
 
 ## [1.8.2] - 2019-07-08
 
diff --git a/src/PhpSpreadsheet/Reader/Html.php b/src/PhpSpreadsheet/Reader/Html.php
index d599424d..ff2c909e 100644
--- a/src/PhpSpreadsheet/Reader/Html.php
+++ b/src/PhpSpreadsheet/Reader/Html.php
@@ -502,10 +502,10 @@ class Html extends BaseReader
                         if (isset($attributeArray['rowspan'], $attributeArray['colspan'])) {
                             //create merging rowspan and colspan
                             $columnTo = $column;
-                            for ($i = 0; $i < $attributeArray['colspan'] - 1; ++$i) {
+                            for ($i = 0; $i < (int) $attributeArray['colspan'] - 1; ++$i) {
                                 ++$columnTo;
                             }
-                            $range = $column . $row . ':' . $columnTo . ($row + $attributeArray['rowspan'] - 1);
+                            $range = $column . $row . ':' . $columnTo . ($row + (int) $attributeArray['rowspan'] - 1);
                             foreach (Coordinate::extractAllCellReferencesInRange($range) as $value) {
                                 $this->rowspan[$value] = true;
                             }
@@ -513,7 +513,7 @@ class Html extends BaseReader
                             $column = $columnTo;
                         } elseif (isset($attributeArray['rowspan'])) {
                             //create merging rowspan
-                            $range = $column . $row . ':' . $column . ($row + $attributeArray['rowspan'] - 1);
+                            $range = $column . $row . ':' . $column . ($row + (int) $attributeArray['rowspan'] - 1);
                             foreach (Coordinate::extractAllCellReferencesInRange($range) as $value) {
                                 $this->rowspan[$value] = true;
                             }
@@ -521,7 +521,7 @@ class Html extends BaseReader
                         } elseif (isset($attributeArray['colspan'])) {
                             //create merging colspan
                             $columnTo = $column;
-                            for ($i = 0; $i < $attributeArray['colspan'] - 1; ++$i) {
+                            for ($i = 0; $i < (int) $attributeArray['colspan'] - 1; ++$i) {
                                 ++$columnTo;
                             }
                             $sheet->mergeCells($column . $row . ':' . $columnTo . $row);
diff --git a/tests/PhpSpreadsheetTests/Reader/HtmlTest.php b/tests/PhpSpreadsheetTests/Reader/HtmlTest.php
index 415f562a..e8b00f1a 100644
--- a/tests/PhpSpreadsheetTests/Reader/HtmlTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/HtmlTest.php
@@ -33,7 +33,7 @@ class HtmlTest extends TestCase
     /**
      * @dataProvider providerCanReadVerySmallFile
      *
-     * @param bool   $expected
+     * @param bool $expected
      * @param string $content
      */
     public function testCanReadVerySmallFile($expected, $content)
@@ -321,4 +321,14 @@ class HtmlTest extends TestCase
     {
         return (new Html())->load($filename);
     }
+
+    public function testRowspanInRendering()
+    {
+        $filename = './data/Reader/HTML/rowspan.html';
+        $reader = new Html();
+        $spreadsheet = $reader->load($filename);
+
+        $actual = $spreadsheet->getActiveSheet()->getMergeCells();
+        self::assertSame(['A2:C2' => 'A2:C2'], $actual);
+    }
 }
diff --git a/tests/data/Reader/HTML/rowspan.html b/tests/data/Reader/HTML/rowspan.html
new file mode 100644
index 00000000..c748c8e3
--- /dev/null
+++ b/tests/data/Reader/HTML/rowspan.html
@@ -0,0 +1,14 @@
+<table>
+    <tbody>
+    <tr>
+        <td>A1</td>
+        <td>B1</td>
+        <td>C1</td>
+        <td>D1</td>
+    </tr>
+    <tr>
+        <td colspan='3"'>A2 with invalid colspan</td>
+        <td>D2<td>
+    </tr>
+    </tbody>
+</table>