diff --git a/src/PHPVideoToolkit/ProcessBuilder.php b/src/PHPVideoToolkit/ProcessBuilder.php
index c18140c..a75a1ad 100644
--- a/src/PHPVideoToolkit/ProcessBuilder.php
+++ b/src/PHPVideoToolkit/ProcessBuilder.php
@@ -151,7 +151,7 @@ protected function _combineArgumentList($commands)
                 foreach ($commands as $argument)
                 {
                     // the array ois a flag for a raw argument
-                    $command_string .= (is_array($argument) === true ? $argument : escapeshellarg($argument)).' ';
+                    $command_string .= (is_array($argument) === true ? $argument : ProcessUtils::escapeArgument($argument)).' ';
                 }
             }
             
diff --git a/src/PHPVideoToolkit/ProcessUtils.php b/src/PHPVideoToolkit/ProcessUtils.php
new file mode 100644
index 0000000..05e4277
--- /dev/null
+++ b/src/PHPVideoToolkit/ProcessUtils.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace PHPVideoToolkit;
+
+/**
+ * ProcessUtils is a bunch of utility methods taken from Symphony.
+ *
+ * This class contains static methods only and is not meant to be instantiated.
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class ProcessUtils
+{
+    /**
+     * This class should not be instantiated.
+     */
+    private function __construct()
+    {
+    }
+
+    /**
+     * Escapes a string to be used as a shell argument.
+     *
+     * @param string $argument The argument that will be escaped
+     *
+     * @return string The escaped argument
+     */
+    public static function escapeArgument($argument)
+    {
+        //Fix for PHP bug #43784 escapeshellarg removes % from given string
+        //Fix for PHP bug #49446 escapeshellarg doesn't work on Windows
+        //@see https://bugs.php.net/bug.php?id=43784
+        //@see https://bugs.php.net/bug.php?id=49446
+        if ('\\' === DIRECTORY_SEPARATOR) {
+            if ('' === $argument) {
+                return escapeshellarg($argument);
+            }
+
+            $escapedArgument = '';
+            $quote = false;
+            foreach (preg_split('/(")/', $argument, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE) as $part) {
+                if ('"' === $part) {
+                    $escapedArgument .= '\\"';
+                } elseif (self::isSurroundedBy($part, '%')) {
+                    // Avoid environment variable expansion
+                    $escapedArgument .= '^%"'.substr($part, 1, -1).'"^%';
+                } else {
+                    // escape trailing backslash
+                    if ('\\' === substr($part, -1)) {
+                        $part .= '\\';
+                    }
+                    $quote = true;
+                    $escapedArgument .= $part;
+                }
+            }
+            if ($quote) {
+                $escapedArgument = '"'.$escapedArgument.'"';
+            }
+
+            return $escapedArgument;
+        }
+
+        return escapeshellarg($argument);
+    }
+
+    private static function isSurroundedBy($arg, $char)
+    {
+        return 2 < strlen($arg) && $char === $arg[0] && $char === $arg[strlen($arg) - 1];
+    }
+}