diff --git a/Project.toml b/Project.toml
index 90e50c4..075e345 100644
--- a/Project.toml
+++ b/Project.toml
@@ -10,15 +10,22 @@ GPUArraysCore = "46192b85-c4d5-4398-a991-12ede77f4527"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 NNlib = "872c559c-99b0-510c-b3b7-b6c96a88d5cd"
 
+[weakdeps]
+CategoricalArrays = "324d7699-5711-5eae-9e2f-1d82baa6b597"
+
+[extensions]
+OneHotArraysCategoricalArraysExt = "CategoricalArrays"
+
 [compat]
 Adapt = "3.0, 4"
 CUDA = "4, 5"
+CategoricalArrays = "0.10.8"
 ChainRulesCore = "1.13"
 Compat = "4.2"
 GPUArraysCore = "0.1, 0.2"
 NNlib = "0.8, 0.9"
 Zygote = "0.6.35"
-julia = "1.6"
+julia = "1.10"
 
 [extras]
 CUDA = "052768ef-5323-5732-b1bb-66c8b64840ba"
@@ -28,4 +35,4 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
 [targets]
-test = ["Test", "CUDA", "JLArrays", "Random", "Zygote"]
+test = ["Test", "CategoricalArrays", "CUDA", "JLArrays", "Random", "Zygote"]
diff --git a/ext/OneHotArraysCategoricalArraysExt.jl b/ext/OneHotArraysCategoricalArraysExt.jl
new file mode 100644
index 0000000..beb14be
--- /dev/null
+++ b/ext/OneHotArraysCategoricalArraysExt.jl
@@ -0,0 +1,11 @@
+module OneHotArraysCategoricalArraysExt
+
+println("loading?")
+
+using OneHotArrays, CategoricalArrays
+
+OneHotArrays.OneHotArray(cv::CategoricalValue) = OneHotVector(cv.ref, length(cv.pool.levels))
+
+OneHotArrays.OneHotArray(ca::CategoricalArray) = OneHotArray(ca.refs, length(ca.pool))
+
+end  # module
diff --git a/test/ext_categorical.jl b/test/ext_categorical.jl
new file mode 100644
index 0000000..d227c19
--- /dev/null
+++ b/test/ext_categorical.jl
@@ -0,0 +1,20 @@
+using Test, OneHotArrays, CategoricalArrays
+
+@testset "CategoricalArrays -> OneHotArrays" begin
+    cval = CategoricalArrays.CategoricalValue('b', CategoricalArray('a':'z'))
+
+    @test OneHotArray(cval) isa OneHotVector
+    @test OneHotArray(cval) == (('a':'z') .== 'b')
+
+    @test_broken OneHotVector(cval) isa OneHotVector  # surely if OneHotArray works, subtypes should too
+    @test_broken convert(OneHotArray, cval) isa OneHotVector
+    @test_broken onehot(cval) isa OneHotVector  # possibly we should define this? Instead?
+
+    cvec = categorical(string.([:a, :b, :b, :c, :d, :e]))
+
+    @test OneHotArray(cvec) isa OneHotMatrix
+    @test size(OneHotArray(cvec)) == (5, 6)
+    @test onecold(OneHotArray(cvec)) == [1, 2, 2, 3, 4, 5]
+
+    @test_broken onehotbatch(cvec) isa OneHotMatrix  # possibly we should define this? Instead?
+end
diff --git a/test/runtests.jl b/test/runtests.jl
index f3e50d1..ca83ee8 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -14,6 +14,10 @@ end
   include("linalg.jl")
 end
 
+@testset "Extensions" begin
+  include("ext_categorical.jl")
+end
+
 using Zygote
 import CUDA
 if CUDA.functional()