diff --git a/src/sync-core.cc b/src/sync-core.cc
index c325eb1..d90c463 100644
--- a/src/sync-core.cc
+++ b/src/sync-core.cc
@@ -288,7 +288,10 @@
   m_rootHash = m_log.RememberStateInStateLog();
   SyncStateMsgPtr diff = m_log.FindStateDifferences(*oldHash, *m_rootHash);
 
-  m_stateMsgCallback(diff);
+  if (diff->state_size() > 0)
+  {
+    m_stateMsgCallback(diff);
+  }
 }
 
 void
@@ -345,3 +348,9 @@
   bytes.resize(size);
   msg->SerializeToArray(head(bytes), size);
 }
+
+sqlite3_int64
+SyncCore::seq(const Name &name)
+{
+  return m_log.SeqNo(name);
+}