diff --git a/src/PhpSpreadsheet/Reader/Xlsx.php b/src/PhpSpreadsheet/Reader/Xlsx.php
index 00d86f00..d94a8852 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx.php
@@ -312,15 +312,16 @@ class Xlsx extends BaseReader
 
     private function castToFormula($c, $r, &$cellDataType, &$value, &$calculatedValue, &$sharedFormulas, $castBaseType): void
     {
+        $attr = $c->f->attributes();
         $cellDataType = 'f';
         $value = "={$c->f}";
         $calculatedValue = self::$castBaseType($c);
 
         // Shared formula?
-        if (isset($c->f['t']) && strtolower((string) $c->f['t']) == 'shared') {
-            $instance = (string) $c->f['si'];
+        if (isset($attr['t']) && strtolower((string) $attr['t']) == 'shared') {
+            $instance = (string) $attr['si'];
 
-            if (!isset($sharedFormulas[(string) $c->f['si']])) {
+            if (!isset($sharedFormulas[(string) $attr['si']])) {
                 $sharedFormulas[$instance] = ['master' => $r, 'formula' => $value];
             } else {
                 $master = Coordinate::indexesFromString($sharedFormulas[$instance]['master']);
diff --git a/tests/PhpSpreadsheetTests/Reader/Xlsx/SharedFormulaTest.php b/tests/PhpSpreadsheetTests/Reader/Xlsx/SharedFormulaTest.php
new file mode 100644
index 00000000..94f8e349
--- /dev/null
+++ b/tests/PhpSpreadsheetTests/Reader/Xlsx/SharedFormulaTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader\Xlsx;
+
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Reader\IReader;
+use PHPUnit\Framework\TestCase;
+
+class SharedFormulaTest extends TestCase
+{
+    /**
+     * @var string
+     */
+    private static $testbook = 'samples/templates/32readwriteAreaChart1.xlsx';
+
+    public function testPreliminaries(): void
+    {
+        $file = 'zip://';
+        $file .= self::$testbook;
+        $file .= '#xl/worksheets/sheet1.xml';
+        $data = file_get_contents($file);
+        // confirm that file contains shared formula
+        if ($data === false) {
+            self::fail('Unable to read file');
+        } else {
+            self::assertStringContainsString('<c r="D6"><f t="shared" ca="1" si="0"/>', $data);
+            self::assertStringContainsString('<c r="E6"><f t="shared" ca="1" si="0"/>', $data);
+        }
+    }
+
+    public function testLoadSheetsXlsxChart(): void
+    {
+        $filename = self::$testbook;
+        $reader = IOFactory::createReader('Xlsx');
+        $spreadsheet = $reader->load($filename, IReader::LOAD_WITH_CHARTS);
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame('=(RANDBETWEEN(-50,250)+100)*10', $sheet->getCell('D6')->getValue());
+        self::assertSame('=(RANDBETWEEN(-50,250)+100)*10', $sheet->getCell('E6')->getValue());
+        $spreadsheet->disconnectWorksheets();
+    }
+}