diff --git a/src/Spout/Reader/XLSX/Helper/SharedStringsHelper.php b/src/Spout/Reader/XLSX/Helper/SharedStringsHelper.php
index 0e88839..415d5cf 100644
--- a/src/Spout/Reader/XLSX/Helper/SharedStringsHelper.php
+++ b/src/Spout/Reader/XLSX/Helper/SharedStringsHelper.php
@@ -80,8 +80,6 @@ class SharedStringsHelper
      *
      * The XML file can be really big with sheets containing a lot of data. That is why
      * we need to use a XML reader that provides streaming like the XMLReader library.
-     * Please note that SimpleXML does not provide such a functionality but since it is faster
-     * and more handy to parse few XML nodes, it is used in combination with XMLReader for that purpose.
      *
      * @return void
      * @throws \Box\Spout\Common\Exception\IOException If sharedStrings.xml can't be read
@@ -91,8 +89,7 @@ class SharedStringsHelper
         $xmlReader = new XMLReader();
         $sharedStringIndex = 0;
 
-        $sharedStringsFilePath = $this->getSharedStringsFilePath();
-        if ($xmlReader->open($sharedStringsFilePath) === false) {
+        if ($xmlReader->openFileInZip($this->filePath, self::SHARED_STRINGS_XML_FILE_PATH) === false) {
             throw new IOException('Could not open "' . self::SHARED_STRINGS_XML_FILE_PATH . '".');
         }
 
@@ -119,14 +116,6 @@ class SharedStringsHelper
         $xmlReader->close();
     }
 
-    /**
-     * @return string The path to the shared strings XML file
-     */
-    protected function getSharedStringsFilePath()
-    {
-        return 'zip://' . $this->filePath . '#' . self::SHARED_STRINGS_XML_FILE_PATH;
-    }
-
     /**
      * Returns the shared strings unique count, as specified in <sst> tag.
      *
diff --git a/src/Spout/Reader/XLSX/RowIterator.php b/src/Spout/Reader/XLSX/RowIterator.php
index 2440593..45069b3 100644
--- a/src/Spout/Reader/XLSX/RowIterator.php
+++ b/src/Spout/Reader/XLSX/RowIterator.php
@@ -128,8 +128,7 @@ class RowIterator implements IteratorInterface
     {
         $this->xmlReader->close();
 
-        $sheetDataFilePath = 'zip://' . $this->filePath . '#' . $this->sheetDataXMLFilePath;
-        if ($this->xmlReader->open($sheetDataFilePath) === false) {
+        if ($this->xmlReader->openFileInZip($this->filePath, $this->sheetDataXMLFilePath) === false) {
             throw new IOException("Could not open \"{$this->sheetDataXMLFilePath}\".");
         }