diff --git a/pyaerocom/colocation_3d.py b/pyaerocom/colocation_3d.py
index 1c060ba70..15259ce5d 100644
--- a/pyaerocom/colocation_3d.py
+++ b/pyaerocom/colocation_3d.py
@@ -1,6 +1,7 @@
 """
 Methods and / or classes to perform colocation
 """
+from __future__ import annotations
 import logging
 import os
 
@@ -12,6 +13,7 @@
 from collections import namedtuple
 from typing import NamedTuple
 
+
 from pyaerocom import __version__ as pya_ver
 from pyaerocom import const
 from pyaerocom.colocateddata import ColocatedData