diff --git a/ankisyncd/media.py b/ankisyncd/media.py
index de9f9ba..9c68c4c 100644
--- a/ankisyncd/media.py
+++ b/ankisyncd/media.py
@@ -47,7 +47,7 @@ def dir(self):
         return self._dir
 
     def lastUsn(self):
-        return self.db.scalar("SELECT usn FROM media ORDER BY usn DESC LIMIT 1") or 0
+        return self.db.scalar("SELECT max(usn) FROM media") or 0
 
     def mediaCount(self):
         return self.db.scalar("SELECT count() FROM media WHERE csum IS NOT NULL")