diff --git a/MysqliDb.php b/MysqliDb.php
index ab88d03..17bf8ae 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -556,6 +556,10 @@ public function rawAddPrefix($query){
         preg_match_all("/(from|into|update|join|describe) [\\'\\´]?([a-zA-Z0-9_-]+)[\\'\\´]?/i", $query, $matches);
         list($from_table, $from, $table) = $matches;
 
+        // Check if there are matches
+        if (empty($table[0]))
+            return $query; 
+
         return str_replace($table[0], self::$prefix.$table[0], $query);
     }