diff --git a/src/ifcopenshell-python/ifcopenshell/geom/occ_utils.py b/src/ifcopenshell-python/ifcopenshell/geom/occ_utils.py
index f2c7dd8f11..21ef97ac65 100644
--- a/src/ifcopenshell-python/ifcopenshell/geom/occ_utils.py
+++ b/src/ifcopenshell-python/ifcopenshell/geom/occ_utils.py
@@ -225,7 +225,10 @@ def serialize_shape(shape):
     shapes.SetFormatNb(2)
 
     shapes.Add(shape)
-    return shapes.WriteToString()
+    if hasattr(shapes, "WriteToString"):
+        return shapes.WriteToString()
+    else:
+        return shapes.Write()
 
 
 def create_shape_from_serialization(