diff --git a/osm_common/fsbase.py b/osm_common/fsbase.py
index 208ab87..7e69613 100644
--- a/osm_common/fsbase.py
+++ b/osm_common/fsbase.py
@@ -82,3 +82,6 @@
 
     def file_delete(self, storage, ignore_non_exist=False):
         raise FsException("Method 'file_delete' not implemented")
+
+    def sync(self):
+        raise FsException("Method 'sync' not implemented")