diff --git a/Project.toml b/Project.toml
index f4f0554..8beb91b 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,11 +1,9 @@
 name = "Roentgen"
 uuid = "b0d14063-c48a-4081-83d5-5a5ab48cb495"
 authors = ["lmejn <33491793+lmejn@users.noreply.github.com>"]
-version = "0.13.6"
+version = "0.13.7"
 
 [deps]
-Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
-CUDA = "052768ef-5323-5732-b1bb-66c8b64840ba"
 CoordinateTransformations = "150eb455-5306-5404-9cee-2592286d6298"
 DICOM = "a26e6606-dd52-5f6a-a97f-4f611373d757"
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
@@ -29,6 +27,13 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 WriteVTK = "64499a7a-5c06-52f2-abe2-ccb03c286192"
 
+[weakdeps]
+Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
+CUDA = "052768ef-5323-5732-b1bb-66c8b64840ba"
+
+[extensions]
+RoentgenCUDAExt = "CUDA"
+
 [compat]
 Adapt = "3"
 CUDA = "4, 5"
@@ -54,4 +59,4 @@ SparseArrays = "1"
 StaticArrays = "1"
 Test = "1"
 WriteVTK = "1"
-julia = "1.8"
+julia = "1.9"
diff --git a/ext/RoentgenCUDAExt.jl b/ext/RoentgenCUDAExt.jl
new file mode 100644
index 0000000..154a62f
--- /dev/null
+++ b/ext/RoentgenCUDAExt.jl
@@ -0,0 +1,32 @@
+module RoentgenCUDAExt
+
+using Roentgen
+
+import Roentgen.AbstractBeamlet, Roentgen.AbstractExternalSurface, Roentgen.AbstractDoseAlgorithm
+
+using CUDA
+import Adapt
+
+function dose_fluence_matrix(::Type{CuArray}, pos, beamlets::AbstractArray{<:AbstractBeamlet},
+                             surf::AbstractExternalSurface, calc::AbstractDoseAlgorithm; kwargs...)
+    D = CUDA.zeros(length(pos), length(beamlets))
+    dose_fluence_matrix!(D, pos, beamlets, surf, calc; kwargs...)
+end
+
+function dose_fluence_matrix!(D::CuArray, pos, beamlets::AbstractArray{<:AbstractBeamlet},
+                              surf::AbstractExternalSurface, calc::AbstractDoseAlgorithm;
+                              maxradius=100.)
+    _assert_size(D, pos, beamlets)
+    D .= point_dose.(vec(pos), permutedims(vec(beamlets)), Ref(surf), Ref(calc), maxradius)
+end
+
+function Adapt.adapt_structure(to, surf::CylindricalSurface)
+    cu_rho = Adapt.adapt_structure(to, surf.rho)
+    CylindricalSurface(surf.y, surf.ϕ, cu_rho)
+end
+
+Adapt.@adapt_structure DoseVolume
+Adapt.@adapt_structure LinearSurface
+Adapt.@adapt_structure FinitePencilBeamKernel
+
+end
diff --git a/src/DoseCalculationAlgorithms/FinitePencilBeamKernel.jl b/src/DoseCalculationAlgorithms/FinitePencilBeamKernel.jl
index 702add0..a4e632c 100644
--- a/src/DoseCalculationAlgorithms/FinitePencilBeamKernel.jl
+++ b/src/DoseCalculationAlgorithms/FinitePencilBeamKernel.jl
@@ -112,8 +112,6 @@ function FinitePencilBeamKernel(parameters::AbstractMatrix, args...)
     FinitePencilBeamKernel(SVector{5}.(eachcol(parameters)), args...)
 end
 
-Adapt.@adapt_structure FinitePencilBeamKernel
-
 """
     FinitePencilBeamKernel(filename::String)
 
diff --git a/src/DoseFluenceMatrix.jl b/src/DoseFluenceMatrix.jl
index bb5dafd..c22329c 100644
--- a/src/DoseFluenceMatrix.jl
+++ b/src/DoseFluenceMatrix.jl
@@ -24,13 +24,6 @@ function dose_fluence_matrix(T::Type{<:AbstractMatrix}, pos, beamlets::AbstractA
     dose_fluence_matrix!(D, pos, beamlets, surf, calc; kwargs...)
 end
 
-function dose_fluence_matrix(::Type{CuArray}, pos, beamlets::AbstractArray{<:AbstractBeamlet},
-                             surf::AbstractExternalSurface, calc::AbstractDoseAlgorithm;
-                             kwargs...)
-    D = CUDA.zeros(length(pos), length(beamlets))
-    dose_fluence_matrix!(D, pos, beamlets, surf, calc; kwargs...)
-end
-
 function dose_fluence_matrix(::Type{SparseMatrixCSC}, pos, beamlets::AbstractArray{<:AbstractBeamlet},
                              surf::AbstractExternalSurface, calc::AbstractDoseAlgorithm;
                              kwargs...)
@@ -93,13 +86,6 @@ function dose_fluence_matrix!(D::AbstractArray, pos, beamlets::AbstractArray{<:A
     D
 end
 
-function dose_fluence_matrix!(D::CuArray, pos, beamlets::AbstractArray{<:AbstractBeamlet},
-                              surf::AbstractExternalSurface, calc::AbstractDoseAlgorithm;
-                              maxradius=100.)
-    _assert_size(D, pos, beamlets)
-    D .= point_dose.(vec(pos), permutedims(vec(beamlets)), Ref(surf), Ref(calc), maxradius)
-end
-
 """
     _assert_size(D, pos, beamlets)
 
diff --git a/src/DoseVolume.jl b/src/DoseVolume.jl
index 656fb87..60f00a2 100644
--- a/src/DoseVolume.jl
+++ b/src/DoseVolume.jl
@@ -44,4 +44,3 @@ function dose_fluence_matrix(T, vol::AbstractDoseVolume, beamlets, calc; kwargs.
         kwargs...)
 end
 
-Adapt.@adapt_structure DoseVolume
diff --git a/src/ExternalSurfaces.jl b/src/ExternalSurfaces.jl
index 40d5a23..91f234f 100644
--- a/src/ExternalSurfaces.jl
+++ b/src/ExternalSurfaces.jl
@@ -194,8 +194,6 @@ position and normal at gantry angles.
 """
 LinearSurface
 
-Adapt.@adapt_structure LinearSurface
-
 LinearSurface(p, n) = LinearSurface(vcat.(p, n))
 
 function LinearSurface(ϕg, p, n)
@@ -363,11 +361,6 @@ function CylindricalSurface(mesh::SimpleMesh, y::AbstractRange, nϕ::Int=181)
     CylindricalSurface(ϕ, y, I, center)
 end
 
-function Adapt.adapt_structure(to, surf::CylindricalSurface)
-    cu_rho = Adapt.adapt_structure(to, surf.rho)
-    CylindricalSurface(surf.y, surf.ϕ, cu_rho)
-end
-
 """
     CylindricalSurface(mesh::SimpleMesh, Δy::Real[, nϕ=181])
 
diff --git a/src/Roentgen.jl b/src/Roentgen.jl
index cb93730..eb177d4 100644
--- a/src/Roentgen.jl
+++ b/src/Roentgen.jl
@@ -4,10 +4,6 @@ module Roentgen
 using SparseArrays
 using StaticArrays
 
-# CUDA
-using CUDA
-import Adapt
-
 # Coordinates
 using CoordinateTransformations
 using Rotations