diff --git a/pytest_tests/testsuites/object/test_object_lock.py b/pytest_tests/testsuites/object/test_object_lock.py
index ea78d9d..c2a9d97 100755
--- a/pytest_tests/testsuites/object/test_object_lock.py
+++ b/pytest_tests/testsuites/object/test_object_lock.py
@@ -1,6 +1,5 @@
 import logging
 import re
-from datetime import datetime
 
 import allure
 import pytest
@@ -30,7 +29,7 @@ from frostfs_testlib.storage.dataclasses.storage_object_info import LockObjectIn
 from frostfs_testlib.storage.dataclasses.wallet import WalletInfo
 from frostfs_testlib.testing.cluster_test_base import ClusterTestBase
 from frostfs_testlib.testing.test_control import expect_not_raises, wait_for_success
-from frostfs_testlib.utils import datetime_utils
+from frostfs_testlib.utils import datetime_utils, string_utils
 
 from pytest_tests.helpers.utility import wait_for_gc_pass_on_storage_nodes
 
@@ -43,7 +42,7 @@ FIXTURE_OBJECT_LIFETIME = 10
 @pytest.fixture(scope="module")
 def user_wallet(credentials_provider: CredentialsProvider, cluster: Cluster) -> WalletInfo:
     with reporter.step("Create user wallet with container"):
-        user = User(f"user_{hex(int(datetime.now().timestamp() * 1000000))}")
+        user = User(string_utils.unique_name("user_"))
         return credentials_provider.GRPC.provide(user, cluster.cluster_nodes[0])
 
 
@@ -67,9 +66,7 @@ def locked_storage_object(
         current_epoch = ensure_fresh_epoch(client_shell, cluster)
         expiration_epoch = current_epoch + FIXTURE_LOCK_LIFETIME
 
-        storage_object = user_container.generate_object(
-            object_size.value, expire_at=current_epoch + FIXTURE_OBJECT_LIFETIME
-        )
+        storage_object = user_container.generate_object(object_size.value, expire_at=current_epoch + FIXTURE_OBJECT_LIFETIME)
         lock_object_id = lock_object(
             storage_object.wallet,
             storage_object.cid,
@@ -78,9 +75,7 @@ def locked_storage_object(
             cluster.default_rpc_endpoint,
             lifetime=FIXTURE_LOCK_LIFETIME,
         )
-        storage_object.locks = [
-            LockObjectInfo(storage_object.cid, lock_object_id, FIXTURE_LOCK_LIFETIME, expiration_epoch)
-        ]
+        storage_object.locks = [LockObjectInfo(storage_object.cid, lock_object_id, FIXTURE_LOCK_LIFETIME, expiration_epoch)]
 
     yield storage_object
 
@@ -142,9 +137,7 @@ class TestObjectLockWithGrpc(ClusterTestBase):
         with reporter.step("Creating locked object"):
             current_epoch = self.get_epoch()
 
-            storage_object = user_container.generate_object(
-                object_size.value, expire_at=current_epoch + FIXTURE_OBJECT_LIFETIME
-            )
+            storage_object = user_container.generate_object(object_size.value, expire_at=current_epoch + FIXTURE_OBJECT_LIFETIME)
             lock_object(
                 storage_object.wallet,
                 storage_object.cid,
@@ -220,9 +213,7 @@ class TestObjectLockWithGrpc(ClusterTestBase):
                 1,
             )
 
-    @allure.title(
-        "Lock must contain valid lifetime or expire_at field: (lifetime={wrong_lifetime}, expire-at={wrong_expire_at})"
-    )
+    @allure.title("Lock must contain valid lifetime or expire_at field: (lifetime={wrong_lifetime}, expire-at={wrong_expire_at})")
     # We operate with only lock object here so no complex object needed in this test
     @pytest.mark.parametrize("object_size", ["simple"], indirect=True)
     @pytest.mark.parametrize(
@@ -675,9 +666,7 @@ class TestObjectLockWithGrpc(ClusterTestBase):
 
         with reporter.step("Generate two objects"):
             for epoch_i in range(2):
-                storage_objects.append(
-                    user_container.generate_object(object_size.value, expire_at=current_epoch + epoch_i + 3)
-                )
+                storage_objects.append(user_container.generate_object(object_size.value, expire_at=current_epoch + epoch_i + 3))
 
         self.tick_epoch()
 
diff --git a/pytest_tests/testsuites/session_token/conftest.py b/pytest_tests/testsuites/session_token/conftest.py
index 713442d..cea75aa 100644
--- a/pytest_tests/testsuites/session_token/conftest.py
+++ b/pytest_tests/testsuites/session_token/conftest.py
@@ -1,10 +1,9 @@
-from datetime import datetime
-
 import pytest
 from frostfs_testlib import reporter
 from frostfs_testlib.credentials.interfaces import CredentialsProvider, User
 from frostfs_testlib.storage.cluster import Cluster
 from frostfs_testlib.storage.dataclasses.wallet import WalletInfo
+from frostfs_testlib.utils import string_utils
 
 
 @pytest.fixture(scope="module")
@@ -15,12 +14,12 @@ def owner_wallet(default_wallet: WalletInfo) -> WalletInfo:
 @pytest.fixture(scope="module")
 def user_wallet(credentials_provider: CredentialsProvider, cluster: Cluster) -> WalletInfo:
     with reporter.step("Create user wallet which will use objects from owner via static session"):
-        user = User(f"user_{hex(int(datetime.now().timestamp() * 1000000))}")
+        user = User(string_utils.unique_name("user_"))
         return credentials_provider.GRPC.provide(user, cluster.cluster_nodes[0])
 
 
 @pytest.fixture(scope="module")
 def stranger_wallet(credentials_provider: CredentialsProvider, cluster: Cluster) -> WalletInfo:
     with reporter.step("Create stranger user wallet which should fail to obtain data"):
-        user = User(f"user_{hex(int(datetime.now().timestamp() * 1000000))}")
+        user = User(string_utils.unique_name("user_"))
         return credentials_provider.GRPC.provide(user, cluster.cluster_nodes[0])