diff --git a/libraries/app/api.cpp b/libraries/app/api.cpp
index d46eab07..209416a6 100644
--- a/libraries/app/api.cpp
+++ b/libraries/app/api.cpp
@@ -169,14 +169,14 @@ namespace graphene { namespace app {
     void network_broadcast_api::broadcast_transaction(const signed_transaction& trx)
     {
        trx.validate();
-       _app.chain_database()->check_tansaction_for_duplicated_operations(trx);
+       database_api( *(_app.chain_database() ) ).check_transaction_for_duplicated_operations(trx);
        _app.chain_database()->push_transaction(trx);
        _app.p2p_node()->broadcast_transaction(trx);
     }
 
     fc::variant network_broadcast_api::broadcast_transaction_synchronous(const signed_transaction& trx)
     {
-       _app.chain_database()->check_tansaction_for_duplicated_operations(trx);
+       database_api( *(_app.chain_database() ) ).check_transaction_for_duplicated_operations(trx);
         
        fc::promise<fc::variant>::ptr prom( new fc::promise<fc::variant>() );
        broadcast_transaction_with_callback( [=]( const fc::variant& v ){
diff --git a/libraries/app/database_api.cpp b/libraries/app/database_api.cpp
index 9047c793..748c5831 100644
--- a/libraries/app/database_api.cpp
+++ b/libraries/app/database_api.cpp
@@ -31,6 +31,7 @@
 #include <fc/smart_ref_impl.hpp>
 
 #include <fc/crypto/hex.hpp>
+#include <fc/crypto/digest.hpp>
 
 #include <boost/range/iterator_range.hpp>
 #include <boost/rational.hpp>
@@ -485,7 +486,7 @@ void database_api_impl::check_transaction_for_duplicated_operations(const signed
    {
       for( auto& operation : (*p_itr)(_db).proposed_transaction.operations )
       {
-         exited_operations_digests.insert( fc::digest(operation) );
+         existed_operations_digests.insert( fc::digest(operation) );
       }
    }