diff --git a/Project.toml b/Project.toml
index ed35dd2f..ff74e438 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "StaticArrays"
 uuid = "90137ffa-7385-5640-81b9-e52037218182"
-version = "1.5.16"
+version = "1.5.17"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
diff --git a/src/lu.jl b/src/lu.jl
index 582487ee..9d2f8e57 100644
--- a/src/lu.jl
+++ b/src/lu.jl
@@ -68,10 +68,6 @@ function _first_zero_on_diagonal(A::StaticLUMatrix{M,N,T}) where {M,N,T}
     end
 end
 
-function _first_zero_on_diagonal(A::LinearAlgebra.AbstractTriangular{<:Any,<:StaticMatrix})
-    _first_zero_on_diagonal(A.data)
-end
-
 issuccess(F::LU) = _first_zero_on_diagonal(F.U) == 0
 
 @generated function _lu(A::StaticLUMatrix{M,N,T}, pivot, check) where {M,N,T}
diff --git a/src/traits.jl b/src/traits.jl
index 94054140..ab1aa366 100644
--- a/src/traits.jl
+++ b/src/traits.jl
@@ -16,7 +16,10 @@ Size(::Type{Transpose{T, A}}) where {T, A <: AbstractVecOrMat{T}} = Size(Size(A)
 Size(::Type{Symmetric{T, A}}) where {T, A <: AbstractMatrix{T}} = Size(A)
 Size(::Type{Hermitian{T, A}}) where {T, A <: AbstractMatrix{T}} = Size(A)
 Size(::Type{Diagonal{T, A}}) where {T, A <: AbstractVector{T}} = Size(Size(A)[1], Size(A)[1])
-Size(::Type{<:LinearAlgebra.AbstractTriangular{T, A}}) where {T,A} = Size(A)
+Size(::Type{UpperTriangular{T, A}}) where {T,A} = Size(A)
+Size(::Type{UnitUpperTriangular{T, A}}) where {T,A} = Size(A)
+Size(::Type{LowerTriangular{T, A}}) where {T,A} = Size(A)
+Size(::Type{UnitLowerTriangular{T, A}}) where {T,A} = Size(A)
 
 struct Length{L}
     function Length{L}() where L
diff --git a/src/triangular.jl b/src/triangular.jl
index 99e5fb80..ef8294df 100644
--- a/src/triangular.jl
+++ b/src/triangular.jl
@@ -1,3 +1,5 @@
+const StaticULT{TA} = Union{UpperTriangular{TA,<:StaticMatrix},LowerTriangular{TA,<:StaticMatrix},UnitUpperTriangular{TA,<:StaticMatrix},UnitLowerTriangular{TA,<:StaticMatrix}}
+
 @inline transpose(A::LowerTriangular{<:Any,<:StaticMatrix}) =
     UpperTriangular(transpose(A.data))
 @inline adjoint(A::LowerTriangular{<:Any,<:StaticMatrix}) =
@@ -14,17 +16,15 @@
     UnitLowerTriangular(transpose(A.data))
 @inline adjoint(A::UnitUpperTriangular{<:Any,<:StaticMatrix}) =
     UnitLowerTriangular(adjoint(A.data))
-@inline Base.:*(A::Adjoint{<:Any,<:StaticVector}, B::LinearAlgebra.AbstractTriangular{<:Any,<:StaticMatrix}) =
+@inline Base.:*(A::Adjoint{<:Any,<:StaticVector}, B::StaticULT{<:Any}) =
     adjoint(adjoint(B) * adjoint(A))
-@inline Base.:*(A::Transpose{<:Any,<:StaticVector}, B::LinearAlgebra.AbstractTriangular{<:Any,<:StaticMatrix}) =
+@inline Base.:*(A::Transpose{<:Any,<:StaticVector}, B::StaticULT{<:Any}) =
     transpose(transpose(B) * transpose(A))
-@inline Base.:*(A::LinearAlgebra.AbstractTriangular{<:Any,<:StaticMatrix}, B::Adjoint{<:Any,<:StaticVector}) =
+@inline Base.:*(A::StaticULT{<:Any}, B::Adjoint{<:Any,<:StaticVector}) =
     adjoint(adjoint(B) * adjoint(A))
-@inline Base.:*(A::LinearAlgebra.AbstractTriangular{<:Any,<:StaticMatrix}, B::Transpose{<:Any,<:StaticVector}) =
+@inline Base.:*(A::StaticULT{<:Any}, B::Transpose{<:Any,<:StaticVector}) =
     transpose(transpose(B) * transpose(A))
 
-const StaticULT{TA} = Union{UpperTriangular{TA,<:StaticMatrix},LowerTriangular{TA,<:StaticMatrix},UnitUpperTriangular{TA,<:StaticMatrix},UnitLowerTriangular{TA,<:StaticMatrix}}
-
 @inline Base.:\(A::StaticULT, B::StaticVecOrMatLike) = _A_ldiv_B(Size(A), Size(B), A, B)
 @inline Base.:/(A::StaticVecOrMatLike, B::StaticULT) = transpose(transpose(B) \ transpose(A))
 
@@ -73,3 +73,7 @@ const StaticULT{TA} = Union{UpperTriangular{TA,<:StaticMatrix},LowerTriangular{T
         @inbounds return similar_type(B, TAB)(tuple($(X...)))
     end
 end
+
+function _first_zero_on_diagonal(A::StaticULT)
+    _first_zero_on_diagonal(A.data)
+end