[ic] Handling charge appears, but not included in total-cost

[DB]

IC 4.9.7

I want to charge a $2.99 handling fee for orders subtotaling less than 
$50. In my include/checkout/shopping_cart I added this

[assign handling=0]
[if type=explicit compare="[calc][subtotal noformat=1] <50[/calc]"]
[assign handling=2.99]

And the handling charge does appear. It does not get added to the 
total-cost however. The docs mention that mv_handling must be set but 
I'm not sure where to do that or if that's even my problem. Any hints?

DB