diff --git a/stdlib/LinearAlgebra/src/diagonal.jl b/stdlib/LinearAlgebra/src/diagonal.jl
index d67c0caab0c0f..ca72743519f86 100644
--- a/stdlib/LinearAlgebra/src/diagonal.jl
+++ b/stdlib/LinearAlgebra/src/diagonal.jl
@@ -483,7 +483,7 @@ rdiv!(A::AbstractMatrix{T}, adjD::Adjoint{<:Any,<:Diagonal{T}}) where {T} =
 rdiv!(A::AbstractMatrix{T}, transD::Transpose{<:Any,<:Diagonal{T}}) where {T} =
     (D = transD.parent; rdiv!(A, D))
 
-(/)(A::Union{StridedMatrix, AbstractTriangular}, D::Diagonal) =
+(/)(A::AbstractMatrix, D::Diagonal) =
     rdiv!((typeof(oneunit(eltype(D))/oneunit(eltype(A)))).(A), D)
 
 (\)(F::Factorization, D::Diagonal) =
diff --git a/stdlib/SparseArrays/src/linalg.jl b/stdlib/SparseArrays/src/linalg.jl
index 6b41431db7e78..070ab01fb0ff7 100644
--- a/stdlib/SparseArrays/src/linalg.jl
+++ b/stdlib/SparseArrays/src/linalg.jl
@@ -156,14 +156,6 @@ function (*)(A::AbstractSparseMatrixCSC, D::Diagonal)
     T = Base.promote_op(*, eltype(D), eltype(A))
     mul!(LinearAlgebra.copy_oftype(A, T), A, D)
 end
-function (\)(D::Diagonal, A::AbstractSparseMatrixCSC)
-    T = Base.promote_op(\, eltype(D), eltype(A))
-    ldiv!(D, LinearAlgebra.copy_oftype(A, T))
-end
-function (/)(A::AbstractSparseMatrixCSC, D::Diagonal)
-    T = Base.promote_op(/, eltype(A), eltype(D))
-    rdiv!(LinearAlgebra.copy_oftype(A, T), D)
-end
 
 # Sparse matrix multiplication as described in [Gustavson, 1978]:
 # http://dl.acm.org/citation.cfm?id=355796