We say that a pure d-dimensional simplicial complex ∆ on n vertices is shelling completable if ∆ can be realized as the initial sequence of some shelling of ∆ (d) n−1 , the d-skeleton of the (n − 1)dimensional simplex. A well-known conjecture of Simon posits that any shellable complex is shelling completable.In this note we prove that vertex decomposable complexes are shelling completable. In fact we show that if ∆ is a vertex decomposable complex then there exists an ordering of its ground set V such that adding the revlex smallest missing (d + 1)-subset of V results in a complex that is again vertex decomposable. We explore applications to matroids, shifted complexes, as well as k-vertex decomposable complexes. We also show that if ∆ is a d-dimensional complex on at most d + 3 vertices then the notions of shellable, vertex decomposable, shelling completable, and extendably shellable are all equivalent.