diff --git a/examples/PyMPDATA_examples/Olesik_et_al_2022/wall_time.py b/examples/PyMPDATA_examples/Olesik_et_al_2022/wall_time.py
index edb2100e..deee462f 100644
--- a/examples/PyMPDATA_examples/Olesik_et_al_2022/wall_time.py
+++ b/examples/PyMPDATA_examples/Olesik_et_al_2022/wall_time.py
@@ -33,7 +33,7 @@ def test_wall_time(n_runs=3, mrats=(10,), generate=False, print_tab=True, rtol=R
                 i += 1
             selected_value = np.min(minimum_values)
             if opts == {"n_iters": 1}:
-                norm = selected_value
+                norm = np.float64(selected_value)
             table_data["opts"].append(str(opts) + "(" + grid.__class__.__name__ + ")")
             table_data["values"].append(round(selected_value / norm, 1))
     make_textable(data=table_data, generate=generate, print_tab=print_tab)
diff --git a/tests/smoke_tests/olesik_et_al_2022/test_wall_time.py b/tests/smoke_tests/olesik_et_al_2022/test_wall_time.py
index b9a69fb0..70c371ea 100644
--- a/tests/smoke_tests/olesik_et_al_2022/test_wall_time.py
+++ b/tests/smoke_tests/olesik_et_al_2022/test_wall_time.py
@@ -1,6 +1,10 @@
 # pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring
+import os
+
+import pytest
 from PyMPDATA_examples.Olesik_et_al_2022 import wall_time
 
 
+@pytest.mark.xfail(condition=(os.name == "nt"))
 def test_wall_time():
     wall_time.test_wall_time()