We demonstrate that warped Minkowski space backgrounds, R n−1,1 × w M d−n , n ≥ 3, that preserve strictly more than 16 supersymmetries in d = 11 and type II d = 10 supergravities and with fields which may not be smooth everywhere are locally isometric to the R d−1,1 Minkowski vacuum. In particular, all such flux compactification vacua of these theories have the same local geometry as the maximally supersymmetric vacuum R n−1,1 × T d−n .