We study generalized diffeomorphisms in exceptional geometry with U-duality group E npnq from an algebraic point of view. By extending the Lie algebra e n to an infinitedimensional Borcherds superalgebra, involving also the extension to e n`1 , the generalized Lie derivatives can be expressed in a simple way, and the expressions take the same form for any n ď 7. The closure of the transformations then follows from the Jacobi identity and the grading of e n`1 with respect to e n .