diff --git a/Duplicati/Library/Main/ForestHash/Database/LocalBackupDatabase.cs b/Duplicati/Library/Main/ForestHash/Database/LocalBackupDatabase.cs
index 14e879c41..688dc7f19 100644
--- a/Duplicati/Library/Main/ForestHash/Database/LocalBackupDatabase.cs
+++ b/Duplicati/Library/Main/ForestHash/Database/LocalBackupDatabase.cs
@@ -343,7 +343,10 @@ namespace Duplicati.Library.Main.ForestHash.Database
                 m_findblocksetCommand.Transaction = transaction;
                 r = m_findblocksetCommand.ExecuteScalar(null, filehash, size);
                 if (r != null && r != DBNull.Value)
+                {
+                    blocksetid = Convert.ToInt64(r);
                 	return false; //Found it
+                }
             }
                 
             using (var tr = new TemporaryTransactionWrapper(m_connection, transaction))