We consider the problem of conjugating a flow on R-d x R to an "integrable" flow (q) over dot = omega and (p) over dot = cp , if possible, with c not equal 0. Our emphasis is on a constructive approach, using a KAM type iteration and analyticity. An application to the periodically forced Van der Pol oscillator is given. (c) 2024 Elsevier Inc. All rights reserved.