diff --git a/ext/BlockBandedMatricesSparseArraysExt.jl b/ext/BlockBandedMatricesSparseArraysExt.jl
index 442415e..e52d549 100644
--- a/ext/BlockBandedMatricesSparseArraysExt.jl
+++ b/ext/BlockBandedMatricesSparseArraysExt.jl
@@ -11,13 +11,14 @@ function sparse(A::BandedBlockBandedMatrix)
     i = Vector{Int}()
     j = Vector{Int}()
     z = Vector{eltype(A)}()
+    m_ax,n_ax = axes(A)
     for J = blockaxes(A,2), K = blockcolsupport(A, J)
         B = view(A, K, J)
         ĩ = _banded_rowval(B)
         j̃ = _banded_colval(B)
         z̃ = _banded_nzval(B)
-        ĩ .+= first(axes(A,1)[K])-1
-        j̃ .+= first(axes(A,2)[J])-1
+        ĩ .+= first(m_ax[K])-1
+        j̃ .+= first(n_ax[J])-1
         append!(i, ĩ)
         append!(j, j̃)
         append!(z, z̃)