diff --git a/src/spaces/cartesianspace.jl b/src/spaces/cartesianspace.jl
index 9f927dac..90fbef30 100644
--- a/src/spaces/cartesianspace.jl
+++ b/src/spaces/cartesianspace.jl
@@ -8,7 +8,7 @@ vector space that is implicitly assumed in most of matrix algebra.
 struct CartesianSpace <: EuclideanSpace{ℝ}
     d::Int
 end
-CartesianSpace(d::Integer; dual = false) = CartesianSpace(Int(d))
+CartesianSpace(d::Integer = 0; dual = false) = CartesianSpace(Int(d))
 
 Base.getindex(::RealNumbers) = CartesianSpace
 Base.getindex(::RealNumbers, d::Int) = CartesianSpace(d)
diff --git a/src/spaces/complexspace.jl b/src/spaces/complexspace.jl
index aa5f7e02..6dfc0972 100644
--- a/src/spaces/complexspace.jl
+++ b/src/spaces/complexspace.jl
@@ -9,7 +9,7 @@ struct ComplexSpace <: EuclideanSpace{ℂ}
   d::Int
   dual::Bool
 end
-ComplexSpace(d::Integer; dual = false) = ComplexSpace(Int(d), dual)
+ComplexSpace(d::Integer = 0; dual = false) = ComplexSpace(Int(d), dual)
 
 # convenience constructor
 Base.:^(::ComplexNumbers, d::Int) = ComplexSpace(d)
diff --git a/src/spaces/generalspace.jl b/src/spaces/generalspace.jl
index 17bb3c38..32f45c10 100644
--- a/src/spaces/generalspace.jl
+++ b/src/spaces/generalspace.jl
@@ -19,7 +19,7 @@ struct GeneralSpace{𝕜} <: ElementarySpace{𝕜}
         end
     end
 end
-GeneralSpace{𝕜}(d::Int; dual::Bool = false, conj::Bool = false) where {𝕜} =
+GeneralSpace{𝕜}(d::Int = 0; dual::Bool = false, conj::Bool = false) where {𝕜} =
     GeneralSpace{𝕜}(d, dual, conj)
 
 dim(V::GeneralSpace) = V.d
diff --git a/src/spaces/representationspace.jl b/src/spaces/representationspace.jl
index f0a386e0..7a95ab72 100644
--- a/src/spaces/representationspace.jl
+++ b/src/spaces/representationspace.jl
@@ -103,12 +103,13 @@ Base.getindex(::ComplexNumbers, d1::Pair{G,Int}, dims::Pair{G,Int}...) where {G<
 # Corresponding methods:
 # properties
 dim(V::GenericRepresentationSpace) =
-    mapreduce(c->dim(c)*V.dims[c], +, keys(V.dims); init = 0)
+    mapreduce(c->dim(c)*V.dims[c], +, keys(V.dims); init = zero(dim(one(sectortype(V)))))
 dim(V::GenericRepresentationSpace{G}, c::G) where {G<:Sector} =
     get(V.dims, isdual(V) ? dual(c) : c, 0)
 
 dim(V::FiniteRepresentationSpace{G}) where {G<:Sector} =
-    reduce(+, dc*dim(c) for (dc,c) in zip(V.dims, values(G)); init = 0)
+    reduce(+, dc*dim(c) for (dc,c) in zip(V.dims, values(G));
+            init = zero(dim(one(sectortype(V)))))
 dim(V::FiniteRepresentationSpace{G}, c::G) where {G<:Sector} =
     V.dims[findindex(values(G), isdual(V) ? dual(c) : c)]
 
diff --git a/test/tensors.jl b/test/tensors.jl
index 4045797c..b5599832 100644
--- a/test/tensors.jl
+++ b/test/tensors.jl
@@ -275,19 +275,19 @@ for (G,V) in ((Trivial, Vtr), (ℤ₂, Vℤ₂), (ℤ₃, Vℤ₃), (U₁, VU₁
                     @test N*N' ≈ id(codomain(N))
                 end
                 @testset "rightorth with $alg" for alg in (TensorKit.RQ(), TensorKit.RQpos(), TensorKit.LQ(), TensorKit.LQpos(), TensorKit.Polar(), TensorKit.SVD(), TensorKit.SDD())
-                    L, Q = @inferred rightorth(t; alg = alg)
-                    @test L == t
-                    @test dim(Q) == dim(R) == 0
+                    L, Q = @inferred rightorth(copy(t'); alg = alg)
+                    @test Q == t'
+                    @test dim(Q) == dim(L) == 0
                 end
                 @testset "rightnull with $alg" for alg in (TensorKit.LQ(), TensorKit.SVD(), TensorKit.SDD())
-                    M = @inferred rightnull(t; alg = alg)
+                    M = @inferred rightnull(copy(t'); alg = alg)
                     @test M*M' ≈ id(codomain(M))
                     @test M'*M ≈ id(domain(M))
                 end
                 @testset "tsvd with $alg" for alg in (TensorKit.SVD(), TensorKit.SDD())
                     U, S, V = @inferred tsvd(t; alg = alg)
                     @test U == t
-                    @test dim(Q) == dim(R) == dim(V)
+                    @test dim(U) == dim(S) == dim(V)
                 end
             end