The higher derivative corrections in double field theory are revisited to first order in α 1 . In first order perturbation theory around flat space, the gauge algebra is α 1 corrected, governed by two parameters a, b. One parameter choice corresponds to bosonic string theory, another to heterotic string theory. These results are generalized to second order in perturbation theory by a Noether procedure. Using consistency conditions derived from the Jacobi identity, it is shown that for general a, b there is no generalized metric formulation. A manifestly background independent formulation is instead given by a frame formalism, with α 1 -deformed frame transformations, as proposed by Marques and Nunez. Their construction is slightly generalized to an α 1 -deformed GLpDqˆGLpDq frame formalism. The perturbation theory around flat space is matched to second order with the results obtained by the Noether procedure. We also obtain a formulation based on the 'non-symmetric' metric E, the sum of metric and b-field. The transformations of E under OpD, Dq receive non-trivial α 1 corrections, unless a "´b, in which case there is a generalized metric formulation, in agreement with previous results in the literature.