Source function in a virtual view, it expects an Object type as the result

On a physical model, I have created a Source Function INSTR with the following parameters:

IN char1 string
IN char2 string
RETURN result Integer

When I use this source function in a virtual view, it expects an Object type as the result of this function. No way to force with an Integer type. So I create an Object column to store this result. But then I create a VDB and I want to deploy it, it tells me that it expects a Integer result and not an Object.