diff --git a/src/Pseudograph.jl b/src/Pseudograph.jl
index 344504f..1f19c5d 100644
--- a/src/Pseudograph.jl
+++ b/src/Pseudograph.jl
@@ -193,5 +193,5 @@ function to_arcdiag(pg::PseudographLabelled{Int}, part::Partition{Int}=Partition
         k += 1
     end
 
-    return ArcDiagramUndirected(n_upper_verts, n_lower_verts, upper_adj, lower_adj)
+    return arc_diagram(Undirected, upper_adj, lower_adj)
 end
diff --git a/test/DeformationBases-test.jl b/test/DeformationBases-test.jl
index 3660562..8dd00ad 100644
--- a/test/DeformationBases-test.jl
+++ b/test/DeformationBases-test.jl
@@ -6,7 +6,7 @@
             sp = smash_product(L, V)
 
             @testset "not all specialisations are zero" begin
-                diag = ArcDiagramUndirected("ABBD,AD")
+                diag = arc_diagram(Undirected, "ABBD,AD")
                 dm = PD.arcdiag_to_deformationmap__so(diag, sp)
                 @test !iszero(dm)
             end