Calculate and previousmonth

Hi, I have table with Date, Customers, Value, and what I need is to get diffrence of Value from previous month.

To get the value from previous month I was trying create Measure like that:

last month value = CALCULATE(sum(Table1[Value]),PREVIOUSMONTH(Table1[Date].[Date]))

But it's not working for me.
I have test measure liek these:

Total Value = sum(Table1[Value])

and these:

previous Month = PREVIOUSMONTH(Table1[Date])

And the last two measures are working for me, the last one it's returnign date with month before - which is correct, but as soon as I'll put them togather in to calculaton formula, I'm getting nothing, blank table with not data.

Waht I'm doing wrong?