diff --git a/src/ifcopenshell-python/ifcopenshell/api/geometry/validate_type.py b/src/ifcopenshell-python/ifcopenshell/api/geometry/validate_type.py
index ef3c9a0bbf..3848a0fb87 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/geometry/validate_type.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/geometry/validate_type.py
@@ -18,12 +18,13 @@
 
 import ifcopenshell.api.geometry
 import ifcopenshell.util.representation
+from typing import Union
 
 
 def validate_type(
     file: ifcopenshell.file,
     representation: ifcopenshell.entity_instance,
-    preferred_item: ifcopenshell.entity_instance | None = None,
+    preferred_item: Union[ifcopenshell.entity_instance, None] = None,
 ) -> bool:
     """Validates the RepresentationType of an IfcShapeRepresentation
 
diff --git a/src/ifcopenshell-python/ifcopenshell/util/representation.py b/src/ifcopenshell-python/ifcopenshell/util/representation.py
index 556067ab06..1255621608 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/representation.py
+++ b/src/ifcopenshell-python/ifcopenshell/util/representation.py
@@ -146,7 +146,7 @@ def get_representation(
             return r
 
 
-def guess_type(items: Sequence[ifcopenshell.entity_instance]) -> str | None:
+def guess_type(items: Sequence[ifcopenshell.entity_instance]) -> Union[str, None]:
     """Guesses the appropriate RepresentationType attribute based on a list of items
 
     :param items: A list of IfcRepresentationItem, typically in an IfcShapeRepresentation