diff --git a/petab/v1/parameters.py b/petab/v1/parameters.py
index 8875c84f..e38c0f00 100644
--- a/petab/v1/parameters.py
+++ b/petab/v1/parameters.py
@@ -3,7 +3,7 @@
 import numbers
 import warnings
 from collections import OrderedDict
-from collections.abc import Iterable, Sequence
+from collections.abc import Iterable, Sequence, Set
 from pathlib import Path
 from typing import (
     Literal,
@@ -258,7 +258,7 @@ def get_required_parameters_for_parameter_table(
     observable_df: pd.DataFrame,
     measurement_df: pd.DataFrame,
     mapping_df: pd.DataFrame = None,
-) -> set[str]:
+) -> Set[str]:
     """
     Get set of parameters which need to go into the parameter table
 
diff --git a/petab/v2/lint.py b/petab/v2/lint.py
index faba72b6..4973d521 100644
--- a/petab/v2/lint.py
+++ b/petab/v2/lint.py
@@ -4,6 +4,7 @@
 import logging
 from abc import ABC, abstractmethod
 from collections import OrderedDict
+from collections.abc import Set
 from dataclasses import dataclass, field
 from enum import IntEnum
 from pathlib import Path
@@ -688,7 +689,7 @@ def append_overrides(overrides):
 
 def get_required_parameters_for_parameter_table(
     problem: Problem,
-) -> set[str]:
+) -> Set[str]:
     """
     Get set of parameters which need to go into the parameter table