Preheat the oven to 350 degrees F. Unfold one of the pie crusts and press into a 9-inch pie dish.
Combine the berries with the flour in a large bowl and toss to coat. Add the sugar, a squeeze of lemon and a dash of salt. Toss to combine. Pour the berries into the prepared pie dish.
Cut the remaining pie crust into 1-inch-wide strips. Arrange the strips on top of the pie in a criss-cross pattern to form a lattice. Bake until the filling is bubbly, 45 to 60 minutes. Serve.