diff --git a/src/onedb/onedb_backend.rb b/src/onedb/onedb_backend.rb
index 2438ec8939..68909a5c98 100644
--- a/src/onedb/onedb_backend.rb
+++ b/src/onedb/onedb_backend.rb
@@ -147,7 +147,7 @@ class OneDBBacKEnd
 
         @db.fetch("SELECT is_slave FROM local_db_versioning "<<
                   "WHERE oid=#{max_oid}") do |row|
-            is_slave = row[:is_slave]
+            is_slave = row[:is_slave] ? 1 : 0
         end
 
         @db.run(