diff --git a/planetmint/backend/tarantool/query.py b/planetmint/backend/tarantool/query.py
index 5339d7a..e387553 100644
--- a/planetmint/backend/tarantool/query.py
+++ b/planetmint/backend/tarantool/query.py
@@ -413,7 +413,7 @@ def store_validator_set(conn, validators_update: dict):
     _validator = conn.run(
         conn.space("validators").select(validators_update["height"], index="height_search", limit=1)
     )
-    unique_id = token_hex(8) if _validator is None or len(_validator.data) == 0 else _validator.data[0][0]
+    unique_id = token_hex(8) if _validator is None or len(_validator) == 0 else _validator.data[0][0]
     conn.run(
         conn.space("validators").upsert((unique_id, validators_update["height"], validators_update["validators"]),
                                         op_list=[('=', 0, unique_id),
diff --git a/tests/utils.py b/tests/utils.py
index ac4d40c..7cd5c0b 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -33,15 +33,16 @@ def flush_localmongo_db(connection, dbname):
 @flush_db.register(TarantoolDBConnection)
 def flush_tarantool_db(connection, dbname):
     for s in SPACE_NAMES:
-        _space = connection.space(space_name=s)
-        _all_data = _space.select([]).data
+        _all_data = connection.run(connection.space(s).select([]))
+        if _all_data is None:
+            continue
         for _id in _all_data:
             if "assets" == s:
-                _space.delete(_id[1])
+                connection.run(connection.space(s).delete(_id[1]), only_data=False)
             elif "abci_chains" == s:
-                _space.delete(_id[2])
+                connection.run(connection.space(s).delete(_id[2], only_data=False))
             else:
-                _space.delete(_id[0])
+                connection.run(connection.space(s).delete(_id[0], only_data=False))
 
 
 def generate_block(planet):