diff --git a/src/Spout/Common/Escaper/ODS.php b/src/Spout/Common/Escaper/ODS.php
index 5e6b695..5f8a7c9 100644
--- a/src/Spout/Common/Escaper/ODS.php
+++ b/src/Spout/Common/Escaper/ODS.php
@@ -14,31 +14,6 @@ class ODS implements EscaperInterface
 {
     use Singleton;
 
-    /** @var string Regex pattern to detect control characters that need to be escaped */
-    protected $escapableControlCharactersPattern;
-
-    /**
-     * Initializes the singleton instance
-     */
-    protected function init()
-    {
-        $this->escapableControlCharactersPattern = $this->getEscapableControlCharactersPattern();
-    }
-
-    /**
-     * @return string Regex pattern containing all escapable control characters
-     */
-    protected function getEscapableControlCharactersPattern()
-    {
-        // control characters values are from 0 to 1F (hex values) in the ASCII table
-        // some characters should not be escaped though: "\t", "\r" and "\n".
-        return '[\x00-\x08' .
-        // skipping "\t" (0x9) and "\n" (0xA)
-        '\x0B-\x0C' .
-        // skipping "\r" (0xD)
-        '\x0E-\x1F]';
-    }
-
     /**
      * Escapes the given string to make it compatible with XLSX
      *
@@ -49,15 +24,24 @@ class ODS implements EscaperInterface
     {
         if (defined('ENT_DISALLOWED')) {
             // 'ENT_DISALLOWED' ensures that invalid characters in the given document type are replaced.
-            // Otherwise characters like a vertical tab "\v" will make the XML document unreadable by the XML processor
+            // Otherwise control characters like a vertical tab "\v" will make the XML document unreadable by the XML processor
             // @link https://github.com/box/spout/issues/329
-            return htmlspecialchars($string, ENT_QUOTES | ENT_DISALLOWED);
+            $replacedString = htmlspecialchars($string, ENT_QUOTES | ENT_DISALLOWED);
         } else {
             // We are on hhvm or any other engine that does not support ENT_DISALLOWED
             $escapedString =  htmlspecialchars($string, ENT_QUOTES);
-            $replacedString = preg_replace('/'.$this->escapableControlCharactersPattern.'/', '�', $escapedString);
-            return $replacedString;
+
+            // control characters values are from 0 to 1F (hex values) in the ASCII table
+            // some characters should not be escaped though: "\t", "\r" and "\n".
+            $regexPattern = '[\x00-\x08' .
+                            // skipping "\t" (0x9) and "\n" (0xA)
+                            '\x0B-\x0C' .
+                            // skipping "\r" (0xD)
+                            '\x0E-\x1F]';
+            $replacedString = preg_replace("/$regexPattern/", '�', $escapedString);
         }
+
+        return $replacedString;
     }
 
     /**