diff --git a/src/ifcopenshell-python/test/util/test_date.py b/src/ifcopenshell-python/test/util/test_date.py
index b96e2066dc..5dc037d8a6 100644
--- a/src/ifcopenshell-python/test/util/test_date.py
+++ b/src/ifcopenshell-python/test/util/test_date.py
@@ -21,7 +21,7 @@ import test.bootstrap
 import ifcopenshell.util.date as subject
 
 
-class TestReadableIFCDuration():
+class TestReadableIFCDuration:
     def test_run(self):
         assert subject.readable_ifc_duration("P0Y0M1DT16H0M0S") == "1D 16h"
         assert subject.readable_ifc_duration("P2Y3M1W4DT5H45M30S") == "2Y 3M 1W 4D 5h 45m 30s"