diff --git a/src/pmc_simulation.jl b/src/pmc_simulation.jl
index 872d0fb07..f250902ee 100644
--- a/src/pmc_simulation.jl
+++ b/src/pmc_simulation.jl
@@ -36,7 +36,7 @@ function _set_up_starting_vectors(
             )
         end
     elseif n_spectral > 1
-        basis = build_basis(ham; minimum_size)
+        basis = build_basis(ham, start_at; minimum_size)
         trunc = BasisSetRepresentation(ham, basis; filter=Returns(false), sizelim=Inf)
         vecs = eigvecs(Matrix(trunc))
         if threading