diff --git a/composer.lock b/composer.lock
index 43c4aeaef..7140b853f 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1803,16 +1803,16 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "2.1.21",
+            "version": "2.1.23",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "1ccf445757458c06a04eb3f803603cb118fe5fa6"
+                "reference": "a34502adbbd5c2366b5a97679848a5ace4f6f2f5"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/1ccf445757458c06a04eb3f803603cb118fe5fa6",
-                "reference": "1ccf445757458c06a04eb3f803603cb118fe5fa6",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/a34502adbbd5c2366b5a97679848a5ace4f6f2f5",
+                "reference": "a34502adbbd5c2366b5a97679848a5ace4f6f2f5",
                 "shasum": ""
             },
             "require": {
@@ -1857,7 +1857,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-07-28T19:35:08+00:00"
+            "time": "2025-09-10T11:42:22+00:00"
         },
         {
             "name": "phpstan/phpstan-deprecation-rules",
@@ -5664,7 +5664,7 @@
         "ext-zip": "*",
         "ext-zlib": "*"
     },
-    "platform-dev": [],
+    "platform-dev": {},
     "platform-overrides": {
         "php": "8.1.99"
     },
diff --git a/infra/LocaleGenerator.php b/infra/LocaleGenerator.php
index 422c0c97f..d99eb8193 100644
--- a/infra/LocaleGenerator.php
+++ b/infra/LocaleGenerator.php
@@ -327,7 +327,7 @@ class LocaleGenerator
             foreach ($cells as $cell) {
                 if ($cell->getValue() != '') {
                     $this->log($cell->getRow() . ' -> ' . $cell->getValueString());
-                    $this->errorCodeMap[$cell->getValue()] = $cell->getRow();
+                    $this->errorCodeMap[$cell->getValueString()] = $cell->getRow();
                 }
             }
         }
@@ -345,7 +345,7 @@ class LocaleGenerator
                 if ($this->isFunctionCategoryEntry($cell)) {
                     if (!empty($cell->getValue())) {
                         $this->log('CATEGORY: ' . $cell->getValueString());
-                        $this->functionNameMap[$cell->getValue()] = $cell->getRow();
+                        $this->functionNameMap[$cell->getValueString()] = $cell->getRow();
                     }
 
                     continue;
@@ -356,7 +356,7 @@ class LocaleGenerator
                         $this->functionNameMap[($cell->getValue() ? 'TRUE' : 'FALSE')] = $cell->getRow();
                     } else {
                         $this->log($cell->getRow() . ' -> ' . $cell->getValueString());
-                        $this->functionNameMap[$cell->getValue()] = $cell->getRow();
+                        $this->functionNameMap[$cell->getValueString()] = $cell->getRow();
                     }
                 }
             }
diff --git a/samples/Wizards/NumberFormat/Currency.php b/samples/Wizards/NumberFormat/Currency.php
index 1e1e53cc4..7484d012f 100644
--- a/samples/Wizards/NumberFormat/Currency.php
+++ b/samples/Wizards/NumberFormat/Currency.php
@@ -104,7 +104,7 @@ if (isset($_POST['submit'])) {
         $helper->log('Unrecognized currency symbol');
     } else {
         try {
-            $negative = $negatives[$_POST['negative']] ?? CurrencyNegative::minus;
+            $negative = $negatives[$_POST['negative']] ?? CurrencyNegative::minus; //* @phpstan-ignore-line
             $wizard = new Wizard\Currency($_POST['currency'], (int) $_POST['decimals'], isset($_POST['thousands']), (bool) $_POST['position']);
             $wizard->setNegative($negative);
             $mask = $wizard->format();
@@ -118,7 +118,7 @@ if (isset($_POST['submit'])) {
                 . ', Wizard\Currency::' . (((bool) $_POST['position']) ? 'LEADING_SYMBOL' : 'TRAILING_SYMBOL')
                 . ');'
             );
-            $helper->log('$wizard->setNegative(' . $negativesString[$_POST['negative']] . ');');
+            $helper->log('$wizard->setNegative(' . $negativesString[$_POST['negative']] . ');'); //* @phpstan-ignore-line
             $helper->log('$mask = $wizard->format();');
             $helper->log('<br />echo (string) $mask;');
             $helper->log('<hr /><b>Mask:</b><br />');
diff --git a/src/PhpSpreadsheet/Calculation/Calculation.php b/src/PhpSpreadsheet/Calculation/Calculation.php
index 2e00977df..a210c88cd 100644
--- a/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -1699,7 +1699,7 @@ class Calculation extends CalculationLocale
                         return $this->raiseFormulaError($e->getMessage(), $e->getCode(), $e);
                     }
                 }
-            } elseif (!is_numeric($token) && !is_object($token) && isset($token, self::BINARY_OPERATORS[$token])) {
+            } elseif (!is_numeric($token) && !is_object($token) && isset($token, self::BINARY_OPERATORS[$token])) { //* @phpstan-ignore-line
                 // if the token is a binary operator, pop the top two values off the stack, do the operation, and push the result back on the stack
                 //    We must have two operands, error if we don't
                 $operand2Data = $stack->pop();
@@ -2879,6 +2879,7 @@ class Calculation extends CalculationLocale
         if ($stack->count() > 0) {
             $o2 = $stack->last();
             if ($o2) {
+                /** @var array{value: string} $o2 */
                 if (isset(self::CALCULATION_OPERATORS[$o2['value']])) {
                     $retVal = (self::OPERATOR_PRECEDENCE[$opCharacter] ?? 0) <= self::OPERATOR_PRECEDENCE[$o2['value']];
                 }
diff --git a/src/PhpSpreadsheet/Calculation/Engine/ArrayArgumentProcessor.php b/src/PhpSpreadsheet/Calculation/Engine/ArrayArgumentProcessor.php
index 7004d0877..687ab1b46 100644
--- a/src/PhpSpreadsheet/Calculation/Engine/ArrayArgumentProcessor.php
+++ b/src/PhpSpreadsheet/Calculation/Engine/ArrayArgumentProcessor.php
@@ -102,7 +102,7 @@ class ArrayArgumentProcessor
     }
 
     /**
-     * @param mixed[] $matrixIndexes
+     * @param array<int|string> $matrixIndexes
      *
      * @return mixed[]
      */
diff --git a/src/PhpSpreadsheet/Calculation/Engine/CyclicReferenceStack.php b/src/PhpSpreadsheet/Calculation/Engine/CyclicReferenceStack.php
index f4806b477..c50fad654 100644
--- a/src/PhpSpreadsheet/Calculation/Engine/CyclicReferenceStack.php
+++ b/src/PhpSpreadsheet/Calculation/Engine/CyclicReferenceStack.php
@@ -21,8 +21,10 @@ class CyclicReferenceStack
 
     /**
      * Push a new entry onto the stack.
+     *
+     * @param int|string $value The value to test
      */
-    public function push(mixed $value): void
+    public function push($value): void
     {
         $this->stack[$value] = $value;
     }
@@ -38,9 +40,9 @@ class CyclicReferenceStack
     /**
      * Test to see if a specified entry exists on the stack.
      *
-     * @param mixed $value The value to test
+     * @param int|string $value The value to test
      */
-    public function onStack(mixed $value): bool
+    public function onStack($value): bool
     {
         return isset($this->stack[$value]);
     }
diff --git a/src/PhpSpreadsheet/Calculation/LookupRef/Matrix.php b/src/PhpSpreadsheet/Calculation/LookupRef/Matrix.php
index 20cdd0697..287e841ca 100644
--- a/src/PhpSpreadsheet/Calculation/LookupRef/Matrix.php
+++ b/src/PhpSpreadsheet/Calculation/LookupRef/Matrix.php
@@ -135,14 +135,14 @@ class Matrix
             return self::extractRowValue($matrix, $rowKeys, $rowNum);
         }
 
-        $columnNum = $columnKeys[--$columnNum];
+        $columnNum = $columnKeys[--$columnNum]; //* @phpstan-ignore-line
         if ($rowNum === 0) {
             return array_map(
                 fn ($value): array => [$value],
                 array_column($matrix, $columnNum)
             );
         }
-        $rowNum = $rowKeys[--$rowNum];
+        $rowNum = $rowKeys[--$rowNum]; //* @phpstan-ignore-line
         /** @var mixed[][] $matrix */
 
         return $matrix[$rowNum][$columnNum];
@@ -159,7 +159,7 @@ class Matrix
         }
 
         $rowNum = $rowKeys[--$rowNum];
-        $row = $matrix[$rowNum];
+        $row = $matrix[$rowNum]; //* @phpstan-ignore-line
         if (is_array($row)) {
             return [$rowNum => $row];
         }
diff --git a/src/PhpSpreadsheet/Calculation/LookupRef/Sort.php b/src/PhpSpreadsheet/Calculation/LookupRef/Sort.php
index 352f5c8cd..78a30a4d7 100644
--- a/src/PhpSpreadsheet/Calculation/LookupRef/Sort.php
+++ b/src/PhpSpreadsheet/Calculation/LookupRef/Sort.php
@@ -335,6 +335,7 @@ class Sort extends LookupRefValidations
         // Building a new array in the correct (sorted) order works; but may be memory heavy for larger arrays
         $sortedArray = [];
         foreach ($sortVector as $index) {
+            /** @var int|string $index */
             $sortedArray[] = $sortArray[$index];
         }
 
diff --git a/src/PhpSpreadsheet/Calculation/MathTrig/Arabic.php b/src/PhpSpreadsheet/Calculation/MathTrig/Arabic.php
index ab58add3a..47c2c9800 100644
--- a/src/PhpSpreadsheet/Calculation/MathTrig/Arabic.php
+++ b/src/PhpSpreadsheet/Calculation/MathTrig/Arabic.php
@@ -23,7 +23,7 @@ class Arabic
     /**
      * Recursively calculate the arabic value of a roman numeral.
      *
-     * @param mixed[] $roman
+     * @param string[] $roman
      */
     private static function calculateArabic(array $roman, int &$sum = 0, int $subtract = 0): int
     {
diff --git a/src/PhpSpreadsheet/Calculation/Statistical/Averages.php b/src/PhpSpreadsheet/Calculation/Statistical/Averages.php
index 55eb2ae80..588098277 100644
--- a/src/PhpSpreadsheet/Calculation/Statistical/Averages.php
+++ b/src/PhpSpreadsheet/Calculation/Statistical/Averages.php
@@ -163,7 +163,7 @@ class Averages extends AggregateBase
             sort($aArgs, SORT_NUMERIC);
             $valueCount = $valueCount / 2;
             if ($valueCount == floor($valueCount)) {
-                $returnValue = ($aArgs[$valueCount--] + $aArgs[$valueCount]) / 2;
+                $returnValue = ($aArgs[$valueCount--] + $aArgs[$valueCount]) / 2; //* @phpstan-ignore-line
             } else {
                 $valueCount = (int) floor($valueCount);
                 $returnValue = $aArgs[$valueCount];
@@ -243,7 +243,7 @@ class Averages extends AggregateBase
                         $maxfreqkey = $key;
                         $maxfreqdatum = $datum;
                     } elseif ($freq == $maxfreq) {
-                        if ($frequencyArray[$key]['index'] < $frequencyArray[$maxfreqkey]['index']) {
+                        if ($frequencyArray[$key]['index'] < $frequencyArray[$maxfreqkey]['index']) { //* @phpstan-ignore-line
                             $maxfreqkey = $key;
                             $maxfreqdatum = $datum;
                         }
diff --git a/src/PhpSpreadsheet/Chart/DataSeriesValues.php b/src/PhpSpreadsheet/Chart/DataSeriesValues.php
index 78a2bbec3..f37893220 100644
--- a/src/PhpSpreadsheet/Chart/DataSeriesValues.php
+++ b/src/PhpSpreadsheet/Chart/DataSeriesValues.php
@@ -333,16 +333,12 @@ class DataSeriesValues extends Properties
      * Method for validating hex color.
      *
      * @param string $color value for color
-     *
-     * @return bool true if validation was successful
      */
-    private function validateColor(string $color): bool
+    private function validateColor(string $color): void
     {
         if (!preg_match('/^[a-f0-9]{6}$/i', $color)) {
             throw new Exception(sprintf('Invalid hex color for chart series (color: "%s")', $color));
         }
-
-        return true;
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Reader/Xls.php b/src/PhpSpreadsheet/Reader/Xls.php
index 3c1ac4f16..29384ff0a 100644
--- a/src/PhpSpreadsheet/Reader/Xls.php
+++ b/src/PhpSpreadsheet/Reader/Xls.php
@@ -140,7 +140,7 @@ class Xls extends XlsBase
     /**
      * REF structures. Only applies to BIFF8.
      *
-     * @var mixed[][]
+     * @var array<int, array{'externalBookIndex': int, 'firstSheetIndex': int, 'lastSheetIndex': int}>
      */
     protected array $ref;
 
@@ -2022,8 +2022,8 @@ class Xls extends XlsBase
 
                     // repeated option flags
                     // OpenOffice.org documentation 5.21
-                    $option = ord($recordData[$pos]);
                     /** @var int $pos */
+                    $option = ord($recordData[$pos]);
                     ++$pos;
 
                     /** @var int $limitpos */
diff --git a/src/PhpSpreadsheet/Reader/Xls/LoadSpreadsheet.php b/src/PhpSpreadsheet/Reader/Xls/LoadSpreadsheet.php
index dda8aadb1..76e4235b8 100644
--- a/src/PhpSpreadsheet/Reader/Xls/LoadSpreadsheet.php
+++ b/src/PhpSpreadsheet/Reader/Xls/LoadSpreadsheet.php
@@ -549,6 +549,7 @@ class LoadSpreadsheet extends Xls
                 foreach ($xls->sharedFormulaParts as $cell => $baseCell) {
                     /** @var int $row */
                     [$column, $row] = Coordinate::coordinateFromString($cell);
+                    /** @var string $baseCell */
                     if ($xls->getReadFilter()->readCell($column, $row, $xls->phpSheet->getTitle())) {
                         /** @var string */
                         $temp = $xls->sharedFormulas[$baseCell];
diff --git a/src/PhpSpreadsheet/Reader/Xlsx.php b/src/PhpSpreadsheet/Reader/Xlsx.php
index c7c171da2..f8a0b1132 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx.php
@@ -1079,7 +1079,8 @@ class Xlsx extends BaseReader
                                             $childNode = $node->addChild('formula1');
                                             if ($childNode !== null) { // null should never happen
                                                 // see https://github.com/phpstan/phpstan/issues/8236
-                                                $childNode[0] = (string) $item->formula1->children(Namespaces::DATA_VALIDATIONS2)->f; // @phpstan-ignore-line
+                                                // resolved with Phpstan 2.1.23
+                                                $childNode[0] = (string) $item->formula1->children(Namespaces::DATA_VALIDATIONS2)->f;
                                             }
                                         }
                                     }
diff --git a/src/PhpSpreadsheet/Reader/Xml/Style/Border.php b/src/PhpSpreadsheet/Reader/Xml/Style/Border.php
index 349eaab60..8a5407d02 100644
--- a/src/PhpSpreadsheet/Reader/Xml/Style/Border.php
+++ b/src/PhpSpreadsheet/Reader/Xml/Style/Border.php
@@ -85,6 +85,7 @@ class Border extends StyleBase
                 }
             }
 
+            /** @var int|string $borderPosition */
             if ($borderPosition) {
                 $style['borders'][$borderPosition] = $thisBorder;
             } elseif ($diagonalDirection) {
@@ -99,6 +100,7 @@ class Border extends StyleBase
     /** @return mixed[] */
     protected function parsePosition(string $borderStyleValue, string $diagonalDirection): array
     {
+        // TODO diagonalDirection seems to return int not string
         $borderStyleValue = strtolower($borderStyleValue);
 
         if (in_array($borderStyleValue, self::BORDER_POSITIONS)) {
diff --git a/src/PhpSpreadsheet/Reader/Xml/Style/NumberFormat.php b/src/PhpSpreadsheet/Reader/Xml/Style/NumberFormat.php
index e6fffe176..1ca825a54 100644
--- a/src/PhpSpreadsheet/Reader/Xml/Style/NumberFormat.php
+++ b/src/PhpSpreadsheet/Reader/Xml/Style/NumberFormat.php
@@ -15,7 +15,7 @@ class NumberFormat extends StyleBase
         $toFormats = ['-', ' '];
 
         foreach ($styleAttributes as $styleAttributeKey => $styleAttributeValue) {
-            $styleAttributeValue = str_replace($fromFormats, $toFormats, $styleAttributeValue);
+            $styleAttributeValue = str_replace($fromFormats, $toFormats, (string) $styleAttributeValue);
 
             switch ($styleAttributeValue) {
                 case 'Short Date':
diff --git a/src/PhpSpreadsheet/Style/Style.php b/src/PhpSpreadsheet/Style/Style.php
index 089c9cccb..feac1cb95 100644
--- a/src/PhpSpreadsheet/Style/Style.php
+++ b/src/PhpSpreadsheet/Style/Style.php
@@ -400,6 +400,7 @@ class Style extends Supervisor
                     }
 
                     // Find existing style by hash.
+                    /** @var string $styleHash */
                     $existingStyle = self::$cachedStyles['styleByHash'][$styleHash] ?? null;
 
                     if (!$existingStyle) {
diff --git a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
index 1ee2eff54..441204ca6 100644
--- a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
+++ b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
@@ -274,7 +274,8 @@ class Rule
                 throw new PhpSpreadsheetException('Invalid rule value for column AutoFilter Rule.');
             }
             //    Set the dateTime grouping that we've anticipated
-            $this->setGrouping(self::DATE_TIME_GROUPS[$grouping]);
+            //    I have no idea what Phpstan is complaining about below
+            $this->setGrouping(self::DATE_TIME_GROUPS[$grouping]); // @phpstan-ignore-line
         }
         $this->value = $value;
 
diff --git a/src/PhpSpreadsheet/Worksheet/Worksheet.php b/src/PhpSpreadsheet/Worksheet/Worksheet.php
index cd7c89a3d..7021d8292 100644
--- a/src/PhpSpreadsheet/Worksheet/Worksheet.php
+++ b/src/PhpSpreadsheet/Worksheet/Worksheet.php
@@ -3005,6 +3005,7 @@ class Worksheet
 
         // Loop through rows
         foreach ($this->rangeToArrayYieldRows($range, $nullValue, $calculateFormulas, $formatData, $returnCellRef, $ignoreHidden, $reduceArrays) as $rowRef => $rowArray) {
+            /** @var int $rowRef */
             $returnValue[$rowRef] = $rowArray;
         }
 
@@ -3040,6 +3041,7 @@ class Worksheet
         foreach ($parts as $part) {
             // Loop through rows
             foreach ($this->rangeToArrayYieldRows($part, $nullValue, $calculateFormulas, $formatData, $returnCellRef, $ignoreHidden, $reduceArrays) as $rowRef => $rowArray) {
+                /** @var int $rowRef */
                 $returnValue[$rowRef] = $rowArray;
             }
         }
diff --git a/src/PhpSpreadsheet/Writer/Html.php b/src/PhpSpreadsheet/Writer/Html.php
index 8ebc4718e..27849bf37 100644
--- a/src/PhpSpreadsheet/Writer/Html.php
+++ b/src/PhpSpreadsheet/Writer/Html.php
@@ -2093,6 +2093,7 @@ class Html extends BaseWriter
         // For each of the omitted rows we found above, the affected rowspans should be subtracted by 1
         if (isset($this->isSpannedRow[$sheetIndex])) {
             foreach ($this->isSpannedRow[$sheetIndex] as $rowIndex) {
+                /** @var int $rowIndex */
                 $adjustedBaseCells = [];
                 $c = -1;
                 $e = $countColumns - 1;
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php b/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php
index 09ce162ca..608eadaf0 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php
@@ -35,6 +35,7 @@ class StringTable extends WriterPart
         foreach ($worksheet->getCellCollection()->getCoordinates() as $coordinate) {
             /** @var Cell $cell */
             $cell = $worksheet->getCellCollection()->get($coordinate);
+            /** @var null|int|RichText|string */
             $cellValue = $cell->getValue();
             if (
                 !is_object($cellValue)
diff --git a/tests/PhpSpreadsheetTests/Issue1449Test.php b/tests/PhpSpreadsheetTests/Issue1449Test.php
index d00b10f6e..211fe52fe 100644
--- a/tests/PhpSpreadsheetTests/Issue1449Test.php
+++ b/tests/PhpSpreadsheetTests/Issue1449Test.php
@@ -7,8 +7,7 @@ use PHPUnit\Framework\TestCase;
 
 class Issue1449Test extends TestCase
 {
-    /** @var bool */
-    private $skipTests = true;
+    protected bool $skipTests = true;
 
     public function testDeleteColumns(): void
     {
diff --git a/tests/PhpSpreadsheetTests/Reader/Gnumeric/GnumericStylesTest.php b/tests/PhpSpreadsheetTests/Reader/Gnumeric/GnumericStylesTest.php
index 429a2ee86..19392acbf 100644
--- a/tests/PhpSpreadsheetTests/Reader/Gnumeric/GnumericStylesTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Gnumeric/GnumericStylesTest.php
@@ -33,7 +33,6 @@ class GnumericStylesTest extends TestCase
         foreach ($expected as $key => $val) {
             $covered[$key] = 0;
         }
-        /** @var mixed[][] */
         $tests = $this->providerBorderStyle();
         foreach ($tests as $test) {
             $covered[$test[0]] = 1;
@@ -88,7 +87,6 @@ class GnumericStylesTest extends TestCase
         foreach ($expected as $key => $val) {
             $covered[$key] = 0;
         }
-        /** @var mixed[][] */
         $tests = $this->providerHorizontal();
         foreach ($tests as $test) {
             $covered[$test[0]] = 1;
@@ -117,7 +115,6 @@ class GnumericStylesTest extends TestCase
         foreach ($expected as $key => $val) {
             $covered[$key] = 0;
         }
-        /** @var mixed[][] */
         $tests = $this->providerUnderline();
         foreach ($tests as $test) {
             $covered[$test[0]] = 1;
@@ -185,6 +182,7 @@ class GnumericStylesTest extends TestCase
         }
     }
 
+    /** @return array<int, array{0: string, 1:string}> */
     public static function providerBorderStyle(): array
     {
         return [
@@ -205,7 +203,7 @@ class GnumericStylesTest extends TestCase
         ];
     }
 
-    /** @return string[][] */
+    /** @return array<int, array{0: string, 1:string}> */
     public static function providerFillType(): array
     {
         return [
@@ -230,6 +228,7 @@ class GnumericStylesTest extends TestCase
         ];
     }
 
+    /** @return array<int, array{0: string, 1:string}> */
     public static function providerHorizontal(): array
     {
         return [
@@ -243,6 +242,7 @@ class GnumericStylesTest extends TestCase
         ];
     }
 
+    /** @return array<int, array{0: string, 1:string}> */
     public static function providerUnderline(): array
     {
         return [