diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 564d600..c72fa3c 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -1019,7 +1019,7 @@
 	protected function _file_mime_type($file)
 	{
 		// We'll need this to validate the MIME info string (e.g. text/plain; charset=us-ascii)
-		$regexp = '/^([a-z\-]+\/[a-z0-9\-]+);\s.+$/';
+		$regexp = '/^([a-z\-]+\/[a-z0-9\-\.\+]+);\s.+$/';
 
 		/* Fileinfo extension - most reliable method
 		 *