diff --git a/Project.toml b/Project.toml
index 23e53ac..ae4403d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "DiagonalArrays"
 uuid = "74fd4be6-21e2-4f6f-823a-4360d37c7a77"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
-version = "0.3.11"
+version = "0.3.12"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
@@ -10,17 +10,10 @@ FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 SparseArraysBase = "0d5efcca-f356-4864-8770-e1ed8d78f208"
 
-[weakdeps]
-TensorAlgebra = "68bd88dc-f39d-4e12-b2ca-f046b68fcc6a"
-
-[extensions]
-DiagonalArraysTensorAlgebraExt = "TensorAlgebra"
-
 [compat]
 ArrayLayouts = "1.10.4"
 DerivableInterfaces = "0.5"
 FillArrays = "1.13.0"
 LinearAlgebra = "1.10.0"
 SparseArraysBase = "0.7.2"
-TensorAlgebra = "0.3.10"
 julia = "1.10"
diff --git a/ext/DiagonalArraysTensorAlgebraExt/DiagonalArraysTensorAlgebraExt.jl b/ext/DiagonalArraysTensorAlgebraExt/DiagonalArraysTensorAlgebraExt.jl
deleted file mode 100644
index fc19745..0000000
--- a/ext/DiagonalArraysTensorAlgebraExt/DiagonalArraysTensorAlgebraExt.jl
+++ /dev/null
@@ -1,36 +0,0 @@
-module DiagonalArraysTensorAlgebraExt
-
-using DiagonalArrays: Delta
-using FillArrays: Eye
-using TensorAlgebra:
-  TensorAlgebra,
-  AbstractBlockPermutation,
-  BlockedTrivialPermutation,
-  BlockedTuple,
-  FusionStyle,
-  fuseaxes,
-  matricize
-
-struct DeltaFusion <: FusionStyle end
-TensorAlgebra.FusionStyle(::Delta) = DeltaFusion()
-function matricize_delta(a::AbstractArray, biperm::AbstractBlockPermutation{2})
-  ax = fuseaxes(axes(a), biperm)
-  return Eye{eltype(a)}(ax)
-end
-function TensorAlgebra.matricize(
-  ::DeltaFusion, a::AbstractArray, biperm::AbstractBlockPermutation{2}
-)
-  return matricize_delta(a, biperm)
-end
-function TensorAlgebra.matricize(
-  ::DeltaFusion, a::AbstractArray, biperm::BlockedTrivialPermutation{2}
-)
-  return matricize_delta(a, biperm)
-end
-
-function TensorAlgebra.unmatricize(::DeltaFusion, a::Eye, ax::BlockedTuple{2})
-  length(a) == prod(length, ax) || throw(DimensionMismatch("reshape sizes don't match"))
-  return Delta{eltype(a)}(Tuple(ax))
-end
-
-end
diff --git a/test/test_tensoralgebraext.jl b/test/test_tensoralgebraext.jl
deleted file mode 100644
index 02c0804..0000000
--- a/test/test_tensoralgebraext.jl
+++ /dev/null
@@ -1,13 +0,0 @@
-using DiagonalArrays: Delta
-using FillArrays: Eye
-using TensorAlgebra: FusionStyle, matricize, tuplemortar, unmatricize
-using Test: @test, @testset
-
-@testset "matricize, unmatricize" begin
-  a = Delta{Float32}(2, 2, 2)
-  m = matricize(a, (1,), (2, 3))
-  @test m ≡ Eye{Float32}(2, 4)
-  @test unmatricize(
-    FusionStyle(a), m, tuplemortar(((axes(a, 1),), (axes(a, 2), axes(a, 3))))
-  ) ≡ a
-end