diff --git a/tests/split_rendering/utils.py b/tests/split_rendering/utils.py
index ffb14eb55aaddca3a5b83514279ebe3efe86f0e9..1d54d24e0818cf1db9f1d08147ec4c1022506991 100644
--- a/tests/split_rendering/utils.py
+++ b/tests/split_rendering/utils.py
@@ -34,7 +34,7 @@ import re
 import sys
 from pathlib import Path
 from tempfile import TemporaryDirectory
-from typing import Tuple
+from typing import Tuple, Optional
 
 import numpy as np
 import pytest
@@ -185,7 +185,7 @@ def run_full_chain_split_rendering(
     get_ssnr=False,
     get_odg=False,
     get_odg_bin=False,
-    delay_profile: Path | None=None,
+    delay_profile: Optional[Path]=None,
 ) -> str:
     """
     Runs the full split rendering chain consisting of