diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index a12fd2f5..49dd41a4 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -6575,16 +6575,6 @@ parameters:
 			count: 3
 			path: tests/PhpSpreadsheetTests/Writer/Html/HtmlCommentsTest.php
 
-		-
-			message: "#^Parameter \\#2 \\$locale of function setlocale expects string\\|null, string\\|false given\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/LocaleFloatsTest.php
-
-		-
-			message: "#^Parameter \\#2 \\$subject of function preg_match expects string, string\\|false given\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/LocaleFloatsTest.php
-
 		-
 			message: "#^Cannot call method getDrawingCollection\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\Worksheet\\|null\\.$#"
 			count: 4
diff --git a/src/PhpSpreadsheet/Calculation/Calculation.php b/src/PhpSpreadsheet/Calculation/Calculation.php
index 0d771ff7..e6b79c7a 100644
--- a/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -4368,7 +4368,7 @@ class Calculation
             $rowKey = array_shift($rKeys);
             $cKeys = array_keys(array_keys($operand[$rowKey]));
             $colKey = array_shift($cKeys);
-            if (ctype_upper($colKey)) {
+            if (ctype_upper("$colKey")) {
                 $operandData['reference'] = $colKey . $rowKey;
             }
         }
diff --git a/src/PhpSpreadsheet/Worksheet/ColumnIterator.php b/src/PhpSpreadsheet/Worksheet/ColumnIterator.php
index 0651a7a4..179e9f27 100644
--- a/src/PhpSpreadsheet/Worksheet/ColumnIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/ColumnIterator.php
@@ -131,10 +131,8 @@ class ColumnIterator implements Iterator
 
     /**
      * Return the current column in this worksheet.
-     *
-     * @return Column
      */
-    public function current()
+    public function current(): Column
     {
         return new Column($this->worksheet, Coordinate::stringFromColumnIndex($this->currentColumnIndex));
     }
diff --git a/src/PhpSpreadsheet/Worksheet/Iterator.php b/src/PhpSpreadsheet/Worksheet/Iterator.php
index 134b619a..a4061b78 100644
--- a/src/PhpSpreadsheet/Worksheet/Iterator.php
+++ b/src/PhpSpreadsheet/Worksheet/Iterator.php
@@ -63,10 +63,8 @@ class Iterator implements \Iterator
 
     /**
      * Are there more Worksheet instances available?
-     *
-     * @return bool
      */
-    public function valid()
+    public function valid(): bool
     {
         return $this->position < $this->subject->getSheetCount() && $this->position >= 0;
     }
diff --git a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
index 6a96a826..fc04ccd3 100644
--- a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
@@ -153,10 +153,8 @@ class RowCellIterator extends CellIterator
 
     /**
      * Indicate if more columns exist in the worksheet range of columns that we're iterating.
-     *
-     * @return bool
      */
-    public function valid()
+    public function valid(): bool
     {
         return $this->currentColumnIndex <= $this->endColumnIndex && $this->currentColumnIndex >= $this->startColumnIndex;
     }
diff --git a/src/PhpSpreadsheet/Worksheet/RowIterator.php b/src/PhpSpreadsheet/Worksheet/RowIterator.php
index 7d49f1ac..7fe0f80b 100644
--- a/src/PhpSpreadsheet/Worksheet/RowIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/RowIterator.php
@@ -115,10 +115,8 @@ class RowIterator implements Iterator
 
     /**
      * Return the current row in this worksheet.
-     *
-     * @return Row
      */
-    public function current()
+    public function current(): Row
     {
         return new Row($this->subject, $this->position);
     }
diff --git a/tests/PhpSpreadsheetTests/Writer/Xlsx/LocaleFloatsTest.php b/tests/PhpSpreadsheetTests/Writer/Xlsx/LocaleFloatsTest.php
index 3a9fb1cc..13a13bc9 100644
--- a/tests/PhpSpreadsheetTests/Writer/Xlsx/LocaleFloatsTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Xlsx/LocaleFloatsTest.php
@@ -31,7 +31,7 @@ class LocaleFloatsTest extends TestCase
 
     protected function tearDown(): void
     {
-        if ($this->localeAdjusted) {
+        if ($this->localeAdjusted && is_string($this->currentLocale)) {
             setlocale(LC_ALL, $this->currentLocale);
         }
     }
@@ -55,12 +55,7 @@ class LocaleFloatsTest extends TestCase
 
         $result = $spreadsheet->getActiveSheet()->getCell('A1')->getValue();
 
-        ob_start();
-        var_dump($result);
-        preg_match('/(?:double|float)\(([^\)]+)\)/mui', ob_get_clean(), $matches);
-        self::assertArrayHasKey(1, $matches);
-        $actual = $matches[1];
-        // From PHP8, https://wiki.php.net/rfc/locale_independent_float_to_string applies
-        self::assertEquals('1,1', $actual);
+        $actual = sprintf('%f', $result);
+        self::assertStringContainsString('1,1', $actual);
     }
 }