How many geometrical isomers (cis and trans forms) does 1,3-dimethylcyclobutane have?

The two ring carbons carrying $\mathrm{CH}{}_3$ each have $\mathrm{H}$ and $\mathrm{CH}{}_3$ as exocyclic groups, so the methyls can be on the same face (cis) or on opposite faces (trans) of the ring. Both forms are achiral. The total is $2$.