diff --git a/src/Spout/Common/Helper/GlobalFunctionsHelper.php b/src/Spout/Common/Helper/GlobalFunctionsHelper.php
index c5d6e31..bd1a0bd 100644
--- a/src/Spout/Common/Helper/GlobalFunctionsHelper.php
+++ b/src/Spout/Common/Helper/GlobalFunctionsHelper.php
@@ -30,7 +30,7 @@ class GlobalFunctionsHelper
      * @see fgets()
      *
      * @param resource $handle
-     * @param int|void $length
+     * @param int|null $length
      * @return string
      */
     public function fgets($handle, $length = null)
@@ -81,9 +81,9 @@ class GlobalFunctionsHelper
      * @see fgetcsv()
      *
      * @param resource $handle
-     * @param int|void $length
-     * @param string|void $delimiter
-     * @param string|void $enclosure
+     * @param int|null $length
+     * @param string|null $delimiter
+     * @param string|null $enclosure
      * @return array
      */
     public function fgetcsv($handle, $length = null, $delimiter = null, $enclosure = null)
@@ -97,8 +97,8 @@ class GlobalFunctionsHelper
      *
      * @param resource $handle
      * @param array $fields
-     * @param string|void $delimiter
-     * @param string|void $enclosure
+     * @param string|null $delimiter
+     * @param string|null $enclosure
      * @return int
      */
     public function fputcsv($handle, array $fields, $delimiter = null, $enclosure = null)
@@ -207,7 +207,7 @@ class GlobalFunctionsHelper
      * Wrapper around global function feof()
      * @see feof()
      *
-     * @param resource
+     * @param resource $handle
      * @return bool
      */
     public function feof($handle)
@@ -232,7 +232,7 @@ class GlobalFunctionsHelper
      * @see basename()
      *
      * @param string $path
-     * @param string|void $suffix
+     * @param string|null $suffix
      * @return string
      */
     public function basename($path, $suffix = null)
diff --git a/src/Spout/Reader/ODS/Helper/CellValueFormatter.php b/src/Spout/Reader/ODS/Helper/CellValueFormatter.php
index 661db30..359fea7 100644
--- a/src/Spout/Reader/ODS/Helper/CellValueFormatter.php
+++ b/src/Spout/Reader/ODS/Helper/CellValueFormatter.php
@@ -127,8 +127,8 @@ class CellValueFormatter
     {
         $nodeValue = $node->getAttribute(self::XML_ATTRIBUTE_VALUE);
         $nodeIntValue = intval($nodeValue);
-        // The "==" is intentionally not a "===" because only the value matters, not the type
-        $cellValue = ($nodeIntValue == $nodeValue) ? $nodeIntValue : floatval($nodeValue);
+        $nodeFloatValue = (float) $nodeValue;
+        $cellValue = ((float) $nodeIntValue === $nodeFloatValue) ? $nodeIntValue : $nodeFloatValue;
         return $cellValue;
     }
 
@@ -141,9 +141,7 @@ class CellValueFormatter
     protected function formatBooleanCellValue($node)
     {
         $nodeValue = $node->getAttribute(self::XML_ATTRIBUTE_BOOLEAN_VALUE);
-        // !! is similar to boolval()
-        $cellValue = !!$nodeValue;
-        return $cellValue;
+        return (bool) $nodeValue;
     }
 
     /**
@@ -162,16 +160,18 @@ class CellValueFormatter
         if ($this->shouldFormatDates) {
             // The date is already formatted in the "p" tag
             $nodeWithValueAlreadyFormatted = $node->getElementsByTagName(self::XML_NODE_P)->item(0);
-            return $nodeWithValueAlreadyFormatted->nodeValue;
+            $cellValue = $nodeWithValueAlreadyFormatted->nodeValue;
         } else {
             // otherwise, get it from the "date-value" attribute
             try {
                 $nodeValue = $node->getAttribute(self::XML_ATTRIBUTE_DATE_VALUE);
-                return new \DateTime($nodeValue);
+                $cellValue = new \DateTime($nodeValue);
             } catch (\Exception $e) {
-                return null;
+                $cellValue = null;
             }
         }
+
+        return $cellValue;
     }
 
     /**
@@ -190,16 +190,18 @@ class CellValueFormatter
         if ($this->shouldFormatDates) {
             // The date is already formatted in the "p" tag
             $nodeWithValueAlreadyFormatted = $node->getElementsByTagName(self::XML_NODE_P)->item(0);
-            return $nodeWithValueAlreadyFormatted->nodeValue;
+            $cellValue = $nodeWithValueAlreadyFormatted->nodeValue;
         } else {
             // otherwise, get it from the "time-value" attribute
             try {
                 $nodeValue = $node->getAttribute(self::XML_ATTRIBUTE_TIME_VALUE);
-                return new \DateInterval($nodeValue);
+                $cellValue = new \DateInterval($nodeValue);
             } catch (\Exception $e) {
-                return null;
+                $cellValue = null;
             }
         }
+
+        return $cellValue;
     }
 
     /**
diff --git a/src/Spout/Reader/ODS/RowIterator.php b/src/Spout/Reader/ODS/RowIterator.php
index e7feeb3..7472c82 100644
--- a/src/Spout/Reader/ODS/RowIterator.php
+++ b/src/Spout/Reader/ODS/RowIterator.php
@@ -311,7 +311,7 @@ class RowIterator implements IteratorInterface
      * row data yet (as we still need to apply the "num-columns-repeated" attribute).
      *
      * @param array $rowData
-     * @param string|int|float|bool|\DateTime|\DateInterval|null The value of the last read cell
+     * @param string|int|float|bool|\DateTime|\DateInterval|null $lastReadCellValue The value of the last read cell
      * @return bool Whether the row is empty
      */
     protected function isEmptyRow($rowData, $lastReadCellValue)
diff --git a/src/Spout/Reader/ODS/SheetIterator.php b/src/Spout/Reader/ODS/SheetIterator.php
index 6986d24..a18dc9f 100644
--- a/src/Spout/Reader/ODS/SheetIterator.php
+++ b/src/Spout/Reader/ODS/SheetIterator.php
@@ -136,7 +136,7 @@ class SheetIterator implements IteratorInterface
      *
      * @param string $sheetName Name of the current sheet
      * @param int $sheetIndex Index of the current sheet
-     * @param string|null Name of the sheet that was defined as active or NULL if none defined
+     * @param string|null $activeSheetName Name of the sheet that was defined as active or NULL if none defined
      * @return bool Whether the current sheet was defined as the active one
      */
     private function isActiveSheet($sheetName, $sheetIndex, $activeSheetName)
diff --git a/src/Spout/Reader/Wrapper/XMLReader.php b/src/Spout/Reader/Wrapper/XMLReader.php
index ffe6818..7f81b43 100644
--- a/src/Spout/Reader/Wrapper/XMLReader.php
+++ b/src/Spout/Reader/Wrapper/XMLReader.php
@@ -115,7 +115,7 @@ class XMLReader extends \XMLReader
      * Move cursor to next node skipping all subtrees
      * @see \XMLReader::next
      *
-     * @param string|void $localName The name of the next node to move to
+     * @param string|null $localName The name of the next node to move to
      * @return bool TRUE on success or FALSE on failure
      * @throws \Box\Spout\Reader\Exception\XMLProcessingException If an error/warning occurred
      */
diff --git a/src/Spout/Reader/XLSX/Helper/CellHelper.php b/src/Spout/Reader/XLSX/Helper/CellHelper.php
index 6077839..0d1dc29 100644
--- a/src/Spout/Reader/XLSX/Helper/CellHelper.php
+++ b/src/Spout/Reader/XLSX/Helper/CellHelper.php
@@ -26,7 +26,7 @@ class CellHelper
      * Calling fillMissingArrayIndexes($dataArray, 'FILL') will return this array: ['FILL', 1, 'FILL', 3]
      *
      * @param array $dataArray The array to fill
-     * @param string|void $fillValue optional
+     * @param string $fillValue optional
      * @return array
      */
     public static function fillMissingArrayIndexes($dataArray, $fillValue = '')
diff --git a/src/Spout/Reader/XLSX/Helper/CellValueFormatter.php b/src/Spout/Reader/XLSX/Helper/CellValueFormatter.php
index 200991c..338ccad 100644
--- a/src/Spout/Reader/XLSX/Helper/CellValueFormatter.php
+++ b/src/Spout/Reader/XLSX/Helper/CellValueFormatter.php
@@ -175,11 +175,14 @@ class CellValueFormatter
         $shouldFormatAsDate = $this->styleManager->shouldFormatNumericValueAsDate($cellStyleId);
 
         if ($shouldFormatAsDate) {
-            return $this->formatExcelTimestampValue(floatval($nodeValue), $cellStyleId);
+            $cellValue = $this->formatExcelTimestampValue(floatval($nodeValue), $cellStyleId);
         } else {
             $nodeIntValue = intval($nodeValue);
-            return ($nodeIntValue == $nodeValue) ? $nodeIntValue : floatval($nodeValue);
+            $nodeFloatValue = (float) $nodeValue;
+            $cellValue = ((float) $nodeIntValue === $nodeFloatValue) ? $nodeIntValue : $nodeFloatValue;
         }
+
+        return $cellValue;
     }
 
     /**
@@ -200,14 +203,16 @@ class CellValueFormatter
 
         if ($nodeValue >= 1) {
             // Values greater than 1 represent "dates". The value 1.0 representing the "base" date: 1900-01-01.
-            return $this->formatExcelTimestampValueAsDateValue($nodeValue, $cellStyleId);
+            $cellValue = $this->formatExcelTimestampValueAsDateValue($nodeValue, $cellStyleId);
         } else if ($nodeValue >= 0) {
             // Values between 0 and 1 represent "times".
-            return $this->formatExcelTimestampValueAsTimeValue($nodeValue, $cellStyleId);
+            $cellValue = $this->formatExcelTimestampValueAsTimeValue($nodeValue, $cellStyleId);
         } else {
             // invalid date
-            return null;
+            $cellValue = null;
         }
+
+        return $cellValue;
     }
 
     /**
@@ -232,10 +237,12 @@ class CellValueFormatter
         if ($this->shouldFormatDates) {
             $styleNumberFormatCode = $this->styleManager->getNumberFormatCode($cellStyleId);
             $phpDateFormat = DateFormatHelper::toPHPDateFormat($styleNumberFormatCode);
-            return $dateObj->format($phpDateFormat);
+            $cellValue = $dateObj->format($phpDateFormat);
         } else {
-            return $dateObj;
+            $cellValue = $dateObj;
         }
+
+        return $cellValue;
     }
 
     /**
@@ -261,13 +268,15 @@ class CellValueFormatter
             if ($this->shouldFormatDates) {
                 $styleNumberFormatCode = $this->styleManager->getNumberFormatCode($cellStyleId);
                 $phpDateFormat = DateFormatHelper::toPHPDateFormat($styleNumberFormatCode);
-                return $dateObj->format($phpDateFormat);
+                $cellValue = $dateObj->format($phpDateFormat);
             } else {
-                return $dateObj;
+                $cellValue = $dateObj;
             }
         } catch (\Exception $e) {
-            return null;
+            $cellValue = null;
         }
+
+        return $cellValue;
     }
 
     /**
@@ -278,9 +287,7 @@ class CellValueFormatter
      */
     protected function formatBooleanCellValue($nodeValue)
     {
-        // !! is similar to boolval()
-        $cellValue = !!$nodeValue;
-        return $cellValue;
+        return (bool) $nodeValue;
     }
 
     /**
@@ -294,9 +301,11 @@ class CellValueFormatter
     {
         // Mitigate thrown Exception on invalid date-time format (http://php.net/manual/en/datetime.construct.php)
         try {
-            return ($this->shouldFormatDates) ? $nodeValue : new \DateTime($nodeValue);
+            $cellValue = ($this->shouldFormatDates) ? $nodeValue : new \DateTime($nodeValue);
         } catch (\Exception $e) {
-            return null;
+            $cellValue = null;
         }
+
+        return $cellValue;
     }
 }
diff --git a/src/Spout/Reader/XLSX/Manager/SharedStringsCaching/CachingStrategyFactory.php b/src/Spout/Reader/XLSX/Manager/SharedStringsCaching/CachingStrategyFactory.php
index ff808e0..b05c896 100644
--- a/src/Spout/Reader/XLSX/Manager/SharedStringsCaching/CachingStrategyFactory.php
+++ b/src/Spout/Reader/XLSX/Manager/SharedStringsCaching/CachingStrategyFactory.php
@@ -89,11 +89,13 @@ class CachingStrategyFactory
 
         if ($memoryAvailable === -1) {
             // if cannot get memory limit or if memory limit set as unlimited, don't trust and play safe
-            return ($sharedStringsUniqueCount < self::MAX_NUM_STRINGS_PER_TEMP_FILE);
+            $isInMemoryStrategyUsageSafe = ($sharedStringsUniqueCount < self::MAX_NUM_STRINGS_PER_TEMP_FILE);
         } else {
             $memoryNeeded = $sharedStringsUniqueCount * self::AMOUNT_MEMORY_NEEDED_PER_STRING_IN_KB;
-            return ($memoryAvailable > $memoryNeeded);
+            $isInMemoryStrategyUsageSafe = ($memoryAvailable > $memoryNeeded);
         }
+
+        return $isInMemoryStrategyUsageSafe;
     }
 
     /**
diff --git a/src/Spout/Reader/XLSX/Manager/SheetManager.php b/src/Spout/Reader/XLSX/Manager/SheetManager.php
index b90d0a8..6da8475 100644
--- a/src/Spout/Reader/XLSX/Manager/SheetManager.php
+++ b/src/Spout/Reader/XLSX/Manager/SheetManager.php
@@ -52,7 +52,7 @@ class SheetManager
     /**
      * @param string $filePath Path of the XLSX file being read
      * @param \Box\Spout\Common\Manager\OptionsManagerInterface $optionsManager Reader's options manager
-     * @param \Box\Spout\Reader\XLSX\Manager\SharedStringsManager Manages shared strings
+     * @param \Box\Spout\Reader\XLSX\Manager\SharedStringsManager $sharedStringsManager Manages shared strings
      * @param \Box\Spout\Common\Helper\Escaper\XLSX $escaper Used to unescape XML data
      * @param EntityFactory $entityFactory Factory to create entities
      */
diff --git a/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php b/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php
index 81609e0..f613e4b 100644
--- a/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php
+++ b/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php
@@ -24,9 +24,9 @@ class BorderBuilder
     }
 
     /**
-     * @param string|void $color Border A RGB color code
-     * @param string|void $width Border width @see BorderPart::allowedWidths
-     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @param string $color Border A RGB color code
+     * @param string $width Border width @see BorderPart::allowedWidths
+     * @param string $style Border style @see BorderPart::allowedStyles
      * @return BorderBuilder
      */
     public function setBorderTop($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
@@ -36,9 +36,9 @@ class BorderBuilder
     }
 
     /**
-     * @param string|void $color Border A RGB color code
-     * @param string|void $width Border width @see BorderPart::allowedWidths
-     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @param string $color Border A RGB color code
+     * @param string $width Border width @see BorderPart::allowedWidths
+     * @param string $style Border style @see BorderPart::allowedStyles
      * @return BorderBuilder
      */
     public function setBorderRight($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
@@ -48,9 +48,9 @@ class BorderBuilder
     }
 
     /**
-     * @param string|void $color Border A RGB color code
-     * @param string|void $width Border width @see BorderPart::allowedWidths
-     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @param string $color Border A RGB color code
+     * @param string $width Border width @see BorderPart::allowedWidths
+     * @param string $style Border style @see BorderPart::allowedStyles
      * @return BorderBuilder
      */
     public function setBorderBottom($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
@@ -60,9 +60,9 @@ class BorderBuilder
     }
 
     /**
-     * @param string|void $color Border A RGB color code
-     * @param string|void $width Border width @see BorderPart::allowedWidths
-     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @param string $color Border A RGB color code
+     * @param string $width Border width @see BorderPart::allowedWidths
+     * @param string $style Border style @see BorderPart::allowedStyles
      * @return BorderBuilder
      */
     public function setBorderLeft($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
diff --git a/src/Spout/Writer/Common/Entity/Cell.php b/src/Spout/Writer/Common/Entity/Cell.php
index ab9f2ff..77b5d08 100644
--- a/src/Spout/Writer/Common/Entity/Cell.php
+++ b/src/Spout/Writer/Common/Entity/Cell.php
@@ -97,15 +97,18 @@ class Cell
     {
         if (CellHelper::isBoolean($value)) {
             return self::TYPE_BOOLEAN;
-        } elseif (CellHelper::isEmpty($value)) {
-            return self::TYPE_EMPTY;
-        } elseif (CellHelper::isNumeric($this->getValue())) {
-            return self::TYPE_NUMERIC;
-        } elseif (CellHelper::isNonEmptyString($value)) {
-            return self::TYPE_STRING;
-        } else {
-            return self::TYPE_ERROR;
         }
+        if (CellHelper::isEmpty($value)) {
+            return self::TYPE_EMPTY;
+        }
+        if (CellHelper::isNumeric($this->getValue())) {
+            return self::TYPE_NUMERIC;
+        }
+        if (CellHelper::isNonEmptyString($value)) {
+            return self::TYPE_STRING;
+        }
+
+        return self::TYPE_ERROR;
     }
 
     /**
diff --git a/src/Spout/Writer/Common/Entity/Style/Border.php b/src/Spout/Writer/Common/Entity/Style/Border.php
index 7046897..f872d34 100644
--- a/src/Spout/Writer/Common/Entity/Style/Border.php
+++ b/src/Spout/Writer/Common/Entity/Style/Border.php
@@ -28,7 +28,7 @@ class Border
     private $parts = [];
 
     /**
-     * @param array|void $borderParts
+     * @param array $borderParts
      */
     public function __construct(array $borderParts = [])
     {
diff --git a/src/Spout/Writer/Common/Entity/Style/Style.php b/src/Spout/Writer/Common/Entity/Style/Style.php
index 16268b1..e82b365 100644
--- a/src/Spout/Writer/Common/Entity/Style/Style.php
+++ b/src/Spout/Writer/Common/Entity/Style/Style.php
@@ -322,7 +322,7 @@ class Style
     }
 
     /**
-     * @param bool|void $shouldWrap Should the text be wrapped
+     * @param bool $shouldWrap Should the text be wrapped
      * @return Style
      */
     public function setShouldWrapText($shouldWrap = true)
diff --git a/src/Spout/Writer/Common/Helper/ZipHelper.php b/src/Spout/Writer/Common/Helper/ZipHelper.php
index f47a240..95130d7 100644
--- a/src/Spout/Writer/Common/Helper/ZipHelper.php
+++ b/src/Spout/Writer/Common/Helper/ZipHelper.php
@@ -65,7 +65,7 @@ class ZipHelper
      * @param \ZipArchive $zip An opened zip archive object
      * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
      * @param string $localFilePath Path of the file to be added, under the root folder
-     * @param string|void $existingFileMode Controls what to do when trying to add an existing file
+     * @param string $existingFileMode Controls what to do when trying to add an existing file
      * @return void
      */
     public function addFileToArchive($zip, $rootFolderPath, $localFilePath, $existingFileMode = self::EXISTING_FILES_OVERWRITE)
@@ -90,7 +90,7 @@ class ZipHelper
      * @param \ZipArchive $zip An opened zip archive object
      * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
      * @param string $localFilePath Path of the file to be added, under the root folder
-     * @param string|void $existingFileMode Controls what to do when trying to add an existing file
+     * @param string $existingFileMode Controls what to do when trying to add an existing file
      * @return void
      */
     public function addUncompressedFileToArchive($zip, $rootFolderPath, $localFilePath, $existingFileMode = self::EXISTING_FILES_OVERWRITE)
@@ -143,7 +143,7 @@ class ZipHelper
     /**
      * @param \ZipArchive $zip An opened zip archive object
      * @param string $folderPath Path to the folder to be zipped
-     * @param string|void $existingFileMode Controls what to do when trying to add an existing file
+     * @param string $existingFileMode Controls what to do when trying to add an existing file
      * @return void
      */
     public function addFolderToArchive($zip, $folderPath, $existingFileMode = self::EXISTING_FILES_OVERWRITE)
diff --git a/tests/Spout/Reader/CSV/ReaderTest.php b/tests/Spout/Reader/CSV/ReaderTest.php
index 4c705cf..e35bb5a 100644
--- a/tests/Spout/Reader/CSV/ReaderTest.php
+++ b/tests/Spout/Reader/CSV/ReaderTest.php
@@ -479,10 +479,10 @@ class ReaderTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @param string $fileName
-     * @param string|void $fieldDelimiter
-     * @param string|void $fieldEnclosure
-     * @param string|void $encoding
-     * @param bool|void $shouldPreserveEmptyRows
+     * @param string $fieldDelimiter
+     * @param string $fieldEnclosure
+     * @param string $encoding
+     * @param bool $shouldPreserveEmptyRows
      * @return array All the read rows the given file
      */
     private function getAllRowsForFile(
diff --git a/tests/Spout/Reader/CSV/SpoutTestStream.php b/tests/Spout/Reader/CSV/SpoutTestStream.php
index fdaeb18..f8409bd 100644
--- a/tests/Spout/Reader/CSV/SpoutTestStream.php
+++ b/tests/Spout/Reader/CSV/SpoutTestStream.php
@@ -81,7 +81,7 @@ class SpoutTestStream
 
     /**
      * @param int $offset
-     * @param int|void $whence
+     * @param int $whence
      * @return bool
      */
     public function stream_seek($offset, $whence = SEEK_SET)
diff --git a/tests/Spout/Reader/ODS/ReaderTest.php b/tests/Spout/Reader/ODS/ReaderTest.php
index f36348f..63810a4 100644
--- a/tests/Spout/Reader/ODS/ReaderTest.php
+++ b/tests/Spout/Reader/ODS/ReaderTest.php
@@ -521,8 +521,8 @@ class ReaderTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @param string $fileName
-     * @param bool|void $shouldFormatDates
-     * @param bool|void $shouldPreserveEmptyRows
+     * @param bool $shouldFormatDates
+     * @param bool $shouldPreserveEmptyRows
      * @return array All the read rows the given file
      */
     private function getAllRowsForFile($fileName, $shouldFormatDates = false, $shouldPreserveEmptyRows = false)
diff --git a/tests/Spout/Reader/XLSX/Manager/StyleManagerTest.php b/tests/Spout/Reader/XLSX/Manager/StyleManagerTest.php
index c9834f1..917cc5f 100644
--- a/tests/Spout/Reader/XLSX/Manager/StyleManagerTest.php
+++ b/tests/Spout/Reader/XLSX/Manager/StyleManagerTest.php
@@ -16,8 +16,8 @@ class StyleManagerTest extends \PHPUnit_Framework_TestCase
 {
 
     /**
-     * @param array|void $styleAttributes
-     * @param array|void $customNumberFormats
+     * @param array $styleAttributes
+     * @param array $customNumberFormats
      * @return StyleManager
      */
     private function getStyleManagerMock($styleAttributes = [], $customNumberFormats = [])
diff --git a/tests/Spout/Reader/XLSX/ReaderTest.php b/tests/Spout/Reader/XLSX/ReaderTest.php
index b9e032e..b6b0313 100644
--- a/tests/Spout/Reader/XLSX/ReaderTest.php
+++ b/tests/Spout/Reader/XLSX/ReaderTest.php
@@ -621,8 +621,8 @@ class ReaderTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @param string $fileName
-     * @param bool|void $shouldFormatDates
-     * @param bool|void $shouldPreserveEmptyRows
+     * @param bool $shouldFormatDates
+     * @param bool $shouldPreserveEmptyRows
      * @return array All the read rows the given file
      */
     private function getAllRowsForFile($fileName, $shouldFormatDates = false, $shouldPreserveEmptyRows = false)
diff --git a/tests/Spout/ReflectionHelper.php b/tests/Spout/ReflectionHelper.php
index df02de8..c6d860f 100644
--- a/tests/Spout/ReflectionHelper.php
+++ b/tests/Spout/ReflectionHelper.php
@@ -51,7 +51,7 @@ class ReflectionHelper
      * @param string $class
      * @param string $valueName
      * @param mixed|null $value
-     * @param bool|void $saveOriginalValue
+     * @param bool $saveOriginalValue
      * @return void
      */
     public static function setStaticValue($class, $valueName, $value, $saveOriginalValue = true)
diff --git a/tests/Spout/Writer/XLSX/WriterWithStyleTest.php b/tests/Spout/Writer/XLSX/WriterWithStyleTest.php
index 34a9db3..2c152cc 100644
--- a/tests/Spout/Writer/XLSX/WriterWithStyleTest.php
+++ b/tests/Spout/Writer/XLSX/WriterWithStyleTest.php
@@ -504,7 +504,8 @@ class WriterWithStyleTest extends \PHPUnit_Framework_TestCase
         $bordersApplied = 0;
         /** @var \DOMElement $node */
         foreach ($styleXfsElements->childNodes as $node) {
-            if ($node->getAttribute('applyBorder') == 1) {
+            $shouldApplyBorder = ((int) $node->getAttribute('applyBorder') === 1);
+            if ($shouldApplyBorder) {
                 $bordersApplied++;
                 $this->assertTrue((int)$node->getAttribute('borderId') > 0, 'BorderId is greater than 0');
             } else {