| Index: Source/bindings/scripts/v8_types.py | 
| diff --git a/Source/bindings/scripts/v8_types.py b/Source/bindings/scripts/v8_types.py | 
| index 1ca7631c8ef85a9400fc9bfc4c11ac834d263bf9..761548761df1a17a1a4d5cdef59d0d8437f3490e 100644 | 
| --- a/Source/bindings/scripts/v8_types.py | 
| +++ b/Source/bindings/scripts/v8_types.py | 
| @@ -719,7 +719,7 @@ def v8_set_return_value_union(idl_type, cpp_value, extended_attributes=None, scr | 
| """ | 
|  | 
| return [ | 
| -        member_type.v8_set_return_value(cpp_value + str(i), | 
| +        member_type.v8_set_return_value(cpp_value.format(index=i), | 
| extended_attributes, | 
| script_wrappable, | 
| release and release[i], | 
|  |