SAP Information Steward - uniqueness profiling - managing null values

Hello

I create a profiling for CUSTOMER ALTKN uniqueness

Is works, but NULL (or blank) is view as a duplicates values

Is it possible to isolate ALTKN=NULL from the Non unique

Have you a good suggested way for this ?

I try doing this by implementing a rule and use "Ignore Null" checkbox but without success

I don't want to create a view for each filed where I want to check uniqueness by profiling ....

Thanks for your help and sharing your experience

Vincent