diff --git a/src/cryptonote_protocol/cryptonote_protocol_defs.h b/src/cryptonote_protocol/cryptonote_protocol_defs.h
index fc2f4c343..a1682ef8c 100644
--- a/src/cryptonote_protocol/cryptonote_protocol_defs.h
+++ b/src/cryptonote_protocol/cryptonote_protocol_defs.h
@@ -271,7 +271,7 @@ namespace cryptonote
     {
       crypto::hash block_hash;
       uint64_t current_blockchain_height;      
-      std::vector<size_t> missing_tx_indices;
+      std::vector<uint64_t> missing_tx_indices;
       
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_VAL_POD_AS_BLOB(block_hash)