I would add the dme.
What I have started doing is including a "Beer Math" section in my brewday checklist. I check my gravity before I move wort to boil. This way I know exactly how much DME to add to meet my expected gravity.
Target Gravity (TG) = (Pre Boil Volume) x (Target Gravity)
Mash Gravity (MG) = (Pre Boil Volume x (Measured Gravity)
(Target Gravity) – (Measured Gravity)/45 DME or 38 LME = LBs to Add
Drinking - Craft Brews
Primary - Surly Bender (clone)
Secondary - Zombiedust (clone)