diff --git a/src/ifcopenshell-python/ifcopenshell/util/unit.py b/src/ifcopenshell-python/ifcopenshell/util/unit.py
index 3ea161561d..f9ac7086ed 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/unit.py
+++ b/src/ifcopenshell-python/ifcopenshell/util/unit.py
@@ -593,7 +593,7 @@ def calculate_unit_scale(ifc_file, unit_type='LENGTHUNIT'):
         while unit.is_a("IfcConversionBasedUnit"):
             unit_scale *= unit.ConversionFactor.ValueComponent.wrappedValue
             unit = unit.ConversionFactor.UnitComponent
-        if unit.is_a("IfcSIUnit")':
+        if unit.is_a("IfcSIUnit"):
             unit_scale *= get_prefix_multiplier(unit.Prefix)
     return unit_scale