diff --git a/Project.toml b/Project.toml
index 2caeebe..f239211 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "DiagonalArrays"
 uuid = "74fd4be6-21e2-4f6f-823a-4360d37c7a77"
-version = "0.3.24"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
+version = "0.3.25"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
@@ -13,16 +13,19 @@ SparseArraysBase = "0d5efcca-f356-4864-8770-e1ed8d78f208"
 
 [weakdeps]
 MatrixAlgebraKit = "6c742aac-3347-4629-af66-fc926824e5e4"
+NamedDimsArrays = "60cbd0c0-df58-4cb7-918c-6f5607b73fde"
 
 [extensions]
 DiagonalArraysMatrixAlgebraKitExt = "MatrixAlgebraKit"
+DiagonalArraysNamedDimsArraysExt = "NamedDimsArrays"
 
 [compat]
 ArrayLayouts = "1.10.4"
 DerivableInterfaces = "0.5.5"
-FillArrays = "1.13.0"
-LinearAlgebra = "1.10.0"
+FillArrays = "1.13"
+LinearAlgebra = "1.10"
 MapBroadcast = "0.1.10"
 MatrixAlgebraKit = "0.2, 0.3, 0.4, 0.5, 0.6"
+NamedDimsArrays = "0.10"
 SparseArraysBase = "0.7.2"
 julia = "1.10"
diff --git a/ext/DiagonalArraysNamedDimsArraysExt/DiagonalArraysNamedDimsArraysExt.jl b/ext/DiagonalArraysNamedDimsArraysExt/DiagonalArraysNamedDimsArraysExt.jl
new file mode 100644
index 0000000..7d30d80
--- /dev/null
+++ b/ext/DiagonalArraysNamedDimsArraysExt/DiagonalArraysNamedDimsArraysExt.jl
@@ -0,0 +1,52 @@
+module DiagonalArraysNamedDimsArraysExt
+
+using DiagonalArrays: DiagonalArrays, δ, delta
+using NamedDimsArrays: AbstractNamedUnitRange, nameddims
+
+function DiagonalArrays.delta(
+        elt::Type{<:Number},
+        is::Tuple{AbstractNamedUnitRange, Vararg{AbstractNamedUnitRange}},
+    )
+    return nameddims(delta(elt, Int.(length.(is))), is)
+end
+# TODO: Make `δ` an alias for `delta` so this isn't needed.
+function DiagonalArrays.δ(
+        elt::Type{<:Number},
+        is::Tuple{AbstractNamedUnitRange, Vararg{AbstractNamedUnitRange}},
+    )
+    return delta(elt, is)
+end
+# TODO: Is this needed?
+function DiagonalArrays.delta(
+        is::Tuple{AbstractNamedUnitRange, Vararg{AbstractNamedUnitRange}}
+    )
+    return delta(Bool, is)
+end
+# TODO: Is this needed?
+function DiagonalArrays.δ(
+        is::Tuple{AbstractNamedUnitRange, Vararg{AbstractNamedUnitRange}}
+    )
+    return delta(is)
+end
+# TODO: Is this needed?
+function DiagonalArrays.delta(
+        elt::Type{<:Number}, i1::AbstractNamedUnitRange, i_rest::AbstractNamedUnitRange...
+    )
+    return delta(elt, (i1, i_rest...))
+end
+# TODO: Is this needed?
+function DiagonalArrays.δ(
+        elt::Type{<:Number}, i1::AbstractNamedUnitRange, i_rest::AbstractNamedUnitRange...
+    )
+    return delta(elt, i1, i_rest...)
+end
+# TODO: Is this needed?
+function DiagonalArrays.delta(i1::AbstractNamedUnitRange, i_rest::AbstractNamedUnitRange...)
+    return delta((i1, i_rest...))
+end
+# TODO: Is this needed?
+function DiagonalArrays.δ(i1::AbstractNamedUnitRange, i_rest::AbstractNamedUnitRange...)
+    return delta(i1, i_rest...)
+end
+
+end
diff --git a/test/Project.toml b/test/Project.toml
index 38d2a92..bc8a7a3 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -1,10 +1,13 @@
 [deps]
+Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 DerivableInterfaces = "6c5e35bf-e59e-4898-b73c-732dcc4ba65f"
 DiagonalArrays = "74fd4be6-21e2-4f6f-823a-4360d37c7a77"
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"
+JLArrays = "27aeb0d3-9eb9-45fb-866b-73c2ecf80fcb"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MatrixAlgebraKit = "6c742aac-3347-4629-af66-fc926824e5e4"
+NamedDimsArrays = "60cbd0c0-df58-4cb7-918c-6f5607b73fde"
 SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 SparseArraysBase = "0d5efcca-f356-4864-8770-e1ed8d78f208"
 StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
@@ -12,14 +15,17 @@ Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
+Adapt = "4.4"
 Aqua = "0.8.9"
 DerivableInterfaces = "0.5"
 DiagonalArrays = "0.3"
 FillArrays = "1"
+JLArrays = "0.3"
 LinearAlgebra = "1"
 MatrixAlgebraKit = "0.2.5, 0.3, 0.4, 0.5, 0.6"
+NamedDimsArrays = "0.10"
 SafeTestsets = "0.1"
-SparseArraysBase = "0.7"
+SparseArraysBase = "0.7.10"
 StableRNGs = "1"
 Suppressor = "0.2"
 Test = "1"
diff --git a/test/test_nameddimsarraysext.jl b/test/test_nameddimsarraysext.jl
new file mode 100644
index 0000000..c574d80
--- /dev/null
+++ b/test/test_nameddimsarraysext.jl
@@ -0,0 +1,38 @@
+using Adapt: adapt
+using DiagonalArrays: DiagonalArray, δ, delta, diagview
+using JLArrays: JLArray
+using NamedDimsArrays: dename, nameddims, namedoneto, inds
+using SparseArraysBase: dense
+using Test: @test, @test_broken, @testset
+
+@testset "NamedDimsArrayExt (eltype=$elt, arraytype=$arrayt)" for elt in (Float64, ComplexF64),
+        arrayt in (Array, JLArray)
+
+    dev = adapt(arrayt)
+    @testset "delta" begin
+        i, j = namedoneto.((2, 2), (:i, :j))
+        for a in (
+                delta(i, j),
+                delta(Bool, i, j),
+                delta((i, j)),
+                delta(Bool, (i, j)),
+                δ(i, j),
+                δ(Bool, i, j),
+                δ((i, j)),
+                δ(Bool, (i, j)),
+            )
+            @test eltype(a) ≡ Bool
+            # TODO: Fix this.
+            @test_broken diagview(a)
+            @test diagview(dename(a)) == ones(2)
+        end
+    end
+    @testset "DiagonalArrays" begin
+        s = dev(DiagonalArray(randn(elt, 3), (3, 3)))
+        a = nameddims(s, (:a, :b))
+        b = dense(a)
+        @test dename(b) == dense(dename(a))
+        @test dename(b) isa arrayt{elt, 2}
+        @test inds(b) == inds(a)
+    end
+end