diff --git a/src/Spout/Common/Helper/FileSystemHelper.php b/src/Spout/Common/Helper/FileSystemHelper.php
index c01d051..d7ca64f 100644
--- a/src/Spout/Common/Helper/FileSystemHelper.php
+++ b/src/Spout/Common/Helper/FileSystemHelper.php
@@ -36,7 +36,7 @@ class FileSystemHelper
     {
         $this->throwIfOperationNotInBaseFolder($parentFolderPath);
 
-        $folderPath = $parentFolderPath . DIRECTORY_SEPARATOR . $folderName;
+        $folderPath = $parentFolderPath . '/' . $folderName;
 
         $wasCreationSuccessful = mkdir($folderPath, 0777, true);
         if (!$wasCreationSuccessful) {
@@ -60,7 +60,7 @@ class FileSystemHelper
     {
         $this->throwIfOperationNotInBaseFolder($parentFolderPath);
 
-        $filePath = $parentFolderPath . DIRECTORY_SEPARATOR . $fileName;
+        $filePath = $parentFolderPath . '/' . $fileName;
 
         $wasCreationSuccessful = file_put_contents($filePath, $fileContents);
         if (!$wasCreationSuccessful) {
diff --git a/src/Spout/Reader/Helper/XLSX/SharedStringsHelper.php b/src/Spout/Reader/Helper/XLSX/SharedStringsHelper.php
index 103f337..1a73fbb 100644
--- a/src/Spout/Reader/Helper/XLSX/SharedStringsHelper.php
+++ b/src/Spout/Reader/Helper/XLSX/SharedStringsHelper.php
@@ -162,12 +162,11 @@ class SharedStringsHelper
     }
 
     /**
-     * @return string The path to the shared strings XML file, working cross-platforms
+     * @return string The path to the shared strings XML file
      */
     protected function getSharedStringsFilePath()
     {
-        $sharedStringsXmlFilePath = str_replace('/', DIRECTORY_SEPARATOR, self::SHARED_STRINGS_XML_FILE_PATH);
-        return 'zip://' . $this->filePath . '#' . $sharedStringsXmlFilePath;
+        return 'zip://' . $this->filePath . '#' . self::SHARED_STRINGS_XML_FILE_PATH;
     }
 
     /**
@@ -250,7 +249,7 @@ class SharedStringsHelper
     protected function getSharedStringTempFilePath($sharedStringIndex)
     {
         $numTempFile = intval($sharedStringIndex / self::MAX_NUM_STRINGS_PER_TEMP_FILE);
-        return $this->tempFolder . DIRECTORY_SEPARATOR . 'sharedstrings' . $numTempFile;
+        return $this->tempFolder . '/sharedstrings' . $numTempFile;
     }
 
     /**
diff --git a/src/Spout/Reader/Helper/XLSX/WorksheetHelper.php b/src/Spout/Reader/Helper/XLSX/WorksheetHelper.php
index 62dab69..d869dd4 100644
--- a/src/Spout/Reader/Helper/XLSX/WorksheetHelper.php
+++ b/src/Spout/Reader/Helper/XLSX/WorksheetHelper.php
@@ -186,8 +186,7 @@ class WorksheetHelper
      */
     protected function getFileAsXMLElementWithNamespace($xmlFilePath, $mainNamespace)
     {
-        $normalizedXmlFilePath = str_replace('/', DIRECTORY_SEPARATOR, $xmlFilePath);
-        $xmlContents = $this->globalFunctionsHelper->file_get_contents('zip://' . $this->filePath . '#' . $normalizedXmlFilePath);
+        $xmlContents = $this->globalFunctionsHelper->file_get_contents('zip://' . $this->filePath . '#' . $xmlFilePath);
 
         $xmlElement = new \SimpleXMLElement($xmlContents);
         $xmlElement->registerXPathNamespace('ns', $mainNamespace);
diff --git a/src/Spout/Reader/Internal/XLSX/Worksheet.php b/src/Spout/Reader/Internal/XLSX/Worksheet.php
index f6bfa9a..5145c28 100644
--- a/src/Spout/Reader/Internal/XLSX/Worksheet.php
+++ b/src/Spout/Reader/Internal/XLSX/Worksheet.php
@@ -33,12 +33,11 @@ class Worksheet
 
     /**
      * @return string Path of the XML file containing the worksheet data,
-     *                without the leading slash and working cross-platforms.
+     *                without the leading slash.
      */
     public function getDataXmlFilePath()
     {
-        $dataXmlFilePath = ltrim($this->dataXmlFilePath, '/');
-        return str_replace('/', DIRECTORY_SEPARATOR, $dataXmlFilePath);
+        return ltrim($this->dataXmlFilePath, '/');
     }
 
     /**
diff --git a/src/Spout/Writer/Helper/XLSX/SharedStringsHelper.php b/src/Spout/Writer/Helper/XLSX/SharedStringsHelper.php
index c0701e0..0838306 100644
--- a/src/Spout/Writer/Helper/XLSX/SharedStringsHelper.php
+++ b/src/Spout/Writer/Helper/XLSX/SharedStringsHelper.php
@@ -36,7 +36,7 @@ EOD;
      */
     public function __construct($xlFolder)
     {
-        $sharedStringsFilePath = $xlFolder . DIRECTORY_SEPARATOR . self::SHARED_STRINGS_FILE_NAME;
+        $sharedStringsFilePath = $xlFolder . '/' . self::SHARED_STRINGS_FILE_NAME;
         $this->sharedStringsFilePointer = fopen($sharedStringsFilePath, 'w');
 
         $this->throwIfSharedStringsFilePointerIsNotAvailable();
diff --git a/src/Spout/Writer/Helper/XLSX/ZipHelper.php b/src/Spout/Writer/Helper/XLSX/ZipHelper.php
index e630d77..429b7a1 100644
--- a/src/Spout/Writer/Helper/XLSX/ZipHelper.php
+++ b/src/Spout/Writer/Helper/XLSX/ZipHelper.php
@@ -33,18 +33,30 @@ class ZipHelper
      */
     protected function addFolderToZip($zip, $folderPath)
     {
-        $folderRealPath = realpath($folderPath) . DIRECTORY_SEPARATOR;
+        $folderRealPath = $this->getNormalizedRealPath($folderPath) . '/';
         $itemIterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($folderPath, \RecursiveDirectoryIterator::SKIP_DOTS), \RecursiveIteratorIterator::SELF_FIRST);
 
         foreach ($itemIterator as $itemInfo) {
-            $itemRealPath = realpath($itemInfo->getPathname());
+            $itemRealPath = $this->getNormalizedRealPath($itemInfo->getPathname());
             $itemLocalPath = str_replace($folderRealPath, '', $itemRealPath);
 
             if ($itemInfo->isFile()) {
-                $zip->addFile($itemInfo->getPathname(), $itemLocalPath);
+                $zip->addFile($itemRealPath, $itemLocalPath);
             } else if ($itemInfo->isDir()) {
                 $zip->addEmptyDir($itemLocalPath);
             }
         }
     }
+
+    /**
+     * Returns canonicalized absolute pathname, containing only forward slashes.
+     *
+     * @param string $path Path to normalize
+     * @return string Normalized and canonicalized path
+     */
+    protected function getNormalizedRealPath($path)
+    {
+        $realPath = realpath($path);
+        return str_replace(DIRECTORY_SEPARATOR, '/', $realPath);
+    }
 }
diff --git a/src/Spout/Writer/Internal/XLSX/Worksheet.php b/src/Spout/Writer/Internal/XLSX/Worksheet.php
index 2dd83c3..b403a17 100644
--- a/src/Spout/Writer/Internal/XLSX/Worksheet.php
+++ b/src/Spout/Writer/Internal/XLSX/Worksheet.php
@@ -56,7 +56,7 @@ EOD;
 
         $this->stringsEscaper = new \Box\Spout\Common\Escaper\XLSX();
 
-        $this->worksheetFilePath = $worksheetFilesFolder . DIRECTORY_SEPARATOR . strtolower($this->externalSheet->getName()) . '.xml';
+        $this->worksheetFilePath = $worksheetFilesFolder . '/' . strtolower($this->externalSheet->getName()) . '.xml';
         $this->startSheet();
     }
 
diff --git a/tests/Spout/Writer/SheetTest.php b/tests/Spout/Writer/SheetTest.php
index d33e860..c9a3e55 100644
--- a/tests/Spout/Writer/SheetTest.php
+++ b/tests/Spout/Writer/SheetTest.php
@@ -90,18 +90,9 @@ class SheetTest extends \PHPUnit_Framework_TestCase
      */
     private function assertSheetNameEquals($expectedName, $resourcePath, $message = '')
     {
-        $pathToWorkbookFile = $resourcePath . $this->normalizePath('#xl/workbook.xml');
+        $pathToWorkbookFile = $resourcePath . '#xl/workbook.xml';
         $xmlContents = file_get_contents('zip://' . $pathToWorkbookFile);
 
         $this->assertContains('<sheet name="' . $expectedName . '"', $xmlContents, $message);
     }
-
-    /**
-     * @param string $path
-     * @return string The path with the correct directory separators, as defined for the current platform
-     */
-    private function normalizePath($path)
-    {
-        return str_replace('/', DIRECTORY_SEPARATOR, $path);
-    }
 }
diff --git a/tests/Spout/Writer/XLSXTest.php b/tests/Spout/Writer/XLSXTest.php
index 4ae642a..0abc252 100644
--- a/tests/Spout/Writer/XLSXTest.php
+++ b/tests/Spout/Writer/XLSXTest.php
@@ -408,7 +408,7 @@ class XLSXTest extends \PHPUnit_Framework_TestCase
     private function assertInlineDataWasWrittenToSheet($fileName, $sheetIndex, $inlineData, $message = '')
     {
         $resourcePath = $this->getGeneratedResourcePath($fileName);
-        $pathToSheetFile = $resourcePath . $this->normalizePath('#xl/worksheets/sheet' . $sheetIndex . '.xml');
+        $pathToSheetFile = $resourcePath . '#xl/worksheets/sheet' . $sheetIndex . '.xml';
         $xmlContents = file_get_contents('zip://' . $pathToSheetFile);
 
         $this->assertContains((string)$inlineData, $xmlContents, $message);
@@ -424,7 +424,7 @@ class XLSXTest extends \PHPUnit_Framework_TestCase
     private function assertInlineDataWasNotWrittenToSheet($fileName, $sheetIndex, $inlineData, $message = '')
     {
         $resourcePath = $this->getGeneratedResourcePath($fileName);
-        $pathToSheetFile = $resourcePath . $this->normalizePath('#xl/worksheets/sheet' . $sheetIndex . '.xml');
+        $pathToSheetFile = $resourcePath . '#xl/worksheets/sheet' . $sheetIndex . '.xml';
         $xmlContents = file_get_contents('zip://' . $pathToSheetFile);
 
         $this->assertNotContains((string)$inlineData, $xmlContents, $message);
@@ -439,18 +439,9 @@ class XLSXTest extends \PHPUnit_Framework_TestCase
     private function assertSharedStringWasWritten($fileName, $sharedString, $message = '')
     {
         $resourcePath = $this->getGeneratedResourcePath($fileName);
-        $pathToSharedStringsFile = $resourcePath . $this->normalizePath('#xl/sharedStrings.xml');
+        $pathToSharedStringsFile = $resourcePath . '#xl/sharedStrings.xml';
         $xmlContents = file_get_contents('zip://' . $pathToSharedStringsFile);
 
         $this->assertContains($sharedString, $xmlContents, $message);
     }
-
-    /**
-     * @param string $path
-     * @return string The path with the correct directory separators, as defined for the current platform
-     */
-    private function normalizePath($path)
-    {
-        return str_replace('/', DIRECTORY_SEPARATOR, $path);
-    }
 }