diff --git a/CodeSniffer/DocGenerators/Generator.php b/CodeSniffer/DocGenerators/Generator.php
index a2a6809acd..51ba0c6f92 100644
--- a/CodeSniffer/DocGenerators/Generator.php
+++ b/CodeSniffer/DocGenerators/Generator.php
@@ -132,8 +132,16 @@ public function generate()
      */
     protected function getStandardFiles()
     {
-        $standardDir = realpath(dirname(__FILE__).'/../Standards/'.$this->_standard);
-        $sniffs      = PHP_CodeSniffer::getSniffFiles($standardDir, $this->_standard);
+        if (is_dir($this->_standard) === true) {
+            // This is a custom standard.
+            $standardDir = $this->_standard;
+            $standard = basename($this->_standard);
+        } else {
+            $standardDir = realpath(dirname(__FILE__).'/../Standards/'.$this->_standard);
+            $standard = $this->_standard;
+        }
+
+        $sniffs = PHP_CodeSniffer::getSniffFiles($standardDir, $standard);
 
         $standardFiles = array();
         foreach ($sniffs as $sniff) {
@@ -147,7 +155,7 @@ protected function getStandardFiles()
                 }
             }
 
-            $standardFile = str_replace('/Sniffs/', '/Docs/', $sniff);
+            $standardFile = str_replace(DIRECTORY_SEPARATOR.'Sniffs'.DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR.'Docs'.DIRECTORY_SEPARATOR, $sniff);
             $standardFile = str_replace('Sniff.php', 'Standard.xml', $standardFile);
 
             if (is_file($standardFile) === true) {