diff --git a/include/class.file.php b/include/class.file.php
index 98b66e46b74d25336a2936b2d41ca531e5e0da44..a8e10eaf2181e7e092b3d63b822367e96183ee39 100644
--- a/include/class.file.php
+++ b/include/class.file.php
@@ -322,7 +322,7 @@ class AttachmentFile {
         }
 
         // Check and see if the file is already on record
-        $sql = 'SELECT id, key FROM '.FILE_TABLE
+        $sql = 'SELECT id, `key` FROM '.FILE_TABLE
             .' WHERE signature='.db_input($file['signature'])
             .' AND size='.db_input($file['size']);