A system and method is disclosed for tracking representations of object properties in modified computational objects. A computational object of the subject technology may include an object property having a first value of a first property type. When the object property is set to a second value of a second property type, a new object map is generated for the computational object, the new object map mapping the object property to the second property type, and transition information in a base object map is updated to designate the new object map instead of a first object map. The first object map is then marked as invalid.