diff --git a/src/adjacency.jl b/src/adjacency.jl
index fb53d2ad..63e4e67e 100644
--- a/src/adjacency.jl
+++ b/src/adjacency.jl
@@ -109,7 +109,7 @@ max_num_targets_per_source(adj::VariableTargetAdjacency) = maximum(adj.colstart[
 Base.size(adj::VariableTargetAdjacency) = (max_num_targets_per_source(adj), num_sources(adj))
 
 
-function Matrix(adj::VariableTargetAdjacency{T}) where {T}
+function Base.Matrix(adj::VariableTargetAdjacency{T}) where {T}
     m = zeros(T, size(adj)...)
     for isrc in 1:num_sources(adj)
         for itgt in 1:num_targets(adj, isrc)
diff --git a/src/io.jl b/src/io.jl
index fe17c2d5..553aa026 100644
--- a/src/io.jl
+++ b/src/io.jl
@@ -1,11 +1,11 @@
 using WriteVTK
 
 # conversion from AbstractElementGeometry to WriteVTK.VTKCellTypes
-VTKCellType(::Type{<:AbstractElementGeometry1D}) = VTKCellTypes.VTK_LINE
-VTKCellType(::Type{<:Triangle2D}) = VTKCellTypes.VTK_TRIANGLE
-VTKCellType(::Type{<:Quadrilateral2D}) = VTKCellTypes.VTK_QUAD
-VTKCellType(::Type{<:Tetrahedron3D}) = VTKCellTypes.VTK_TETRA
-VTKCellType(::Type{<:Hexahedron3D}) = VTKCellTypes.VTK_HEXAHEDRON
+WriteVTK.VTKCellType(::Type{<:AbstractElementGeometry1D}) = VTKCellTypes.VTK_LINE
+WriteVTK.VTKCellType(::Type{<:Triangle2D}) = VTKCellTypes.VTK_TRIANGLE
+WriteVTK.VTKCellType(::Type{<:Quadrilateral2D}) = VTKCellTypes.VTK_QUAD
+WriteVTK.VTKCellType(::Type{<:Tetrahedron3D}) = VTKCellTypes.VTK_TETRA
+WriteVTK.VTKCellType(::Type{<:Hexahedron3D}) = VTKCellTypes.VTK_HEXAHEDRON
 
 """
 $(TYPEDSIGNATURES)