A milestone for the Commonwealth’s pot proponents, Massachusetts is set to welcome the opening of its first marijuana dispensary on Wednesday.

The Salem dispensary, called Alternative Therapies Group, will be the first of its kind in the state following a successful bid in 2012 to legalize medical marijuana possession for qualified patients. 

Gov. Charlie Baker issued a one-time, temporary three-month waiver to ATG on Friday. The dispensary asked for the waiver after delays in getting state laboratories ready to conduct quality tests. 

“Patients have waited to access marijuana for medical purposes for far too long,” Baker said in a statement.