diff --git a/ext/FiniteDiffBandedMatricesExt.jl b/ext/FiniteDiffBandedMatricesExt.jl
index 63f2fb2..5a2cbbc 100644
--- a/ext/FiniteDiffBandedMatricesExt.jl
+++ b/ext/FiniteDiffBandedMatricesExt.jl
@@ -10,11 +10,11 @@ end
 
 FiniteDiff._use_findstructralnz(::BandedMatrices.BandedMatrix) = false
 
-@inline function FiniteDiff._colorediteration!(Jac::BandedMatrices.BandedMatrix,
+@inline function FiniteDiff._colorediteration!(Jac::Union{BandedMatrices.BandedMatrix,Array},
                                     sparsity::BandedMatrices.BandedMatrix,
                                     rows_index,cols_index,vfx,colorvec,color_i,ncols)
     nrows = size(Jac,1)
-    l,u = BandedMatrices.bandwidths(Jac)
+    l,u = BandedMatrices.bandwidths(sparsity)
     #data = BandedMatrices.bandeddata(Jac)
     for col_index in max(1,1-l):min(ncols,ncols+u)
         if colorvec[col_index] == color_i