diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 57208c9..b1f5ecc 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -534,7 +534,7 @@
 		}
 
 		// IIS environment likely? Use 'refresh' for better compatibility
-		if (DIRECTORY_SEPARATOR !== '/' && $method === 'auto')
+		if ($method === 'auto' && isset($_SERVER['SERVER_SOFTWARE']) && strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS') !== FALSE)
 		{
 			$method = 'refresh';
 		}