diff --git a/src/state-server.cc b/src/state-server.cc
index 89b6095..f0616b0 100644
--- a/src/state-server.cc
+++ b/src/state-server.cc
@@ -135,7 +135,7 @@
   Object id;
 
   id.push_back (Pair ("userName", boost::lexical_cast<string> (name)));
-  id.push_back (Pair ("seqNo",    seq_no));
+  id.push_back (Pair ("seqNo",    static_cast<int64_t> (seq_no)));
 
   json.push_back (Pair ("id", id));