diff --git a/Project.toml b/Project.toml
index b4e4ae1..1ea7487 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "QuantumOpticsBase"
 uuid = "4f57444f-1401-5e15-980d-4471b28d5678"
-version = "0.5.1"
+version = "0.5.2"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
diff --git a/src/operators_dense.jl b/src/operators_dense.jl
index e36f17f..18285fb 100644
--- a/src/operators_dense.jl
+++ b/src/operators_dense.jl
@@ -1,3 +1,4 @@
+import QuantumInterface
 import Base: isequal, ==, +, -, *, /, Broadcast
 import Adapt
 using Base.Cartesian
@@ -27,6 +28,8 @@ Operator(qets::AbstractVector{<:Ket}) = Operator(first(qets).basis, GenericBasis
 Operator(basis_r::Basis,qets::AbstractVector{<:Ket}) = Operator(first(qets).basis, basis_r, qets)
 Operator(basis_l::BL,basis_r::BR,qets::AbstractVector{<:Ket}) where {BL,BR} = Operator{BL,BR}(basis_l, basis_r, reduce(hcat, getfield.(qets, :data)))
 
+QuantumInterface.traceout!(s::QuantumOpticsBase.Operator, i) = QuantumInterface.ptrace(s,i)
+
 Base.zero(op::Operator) = Operator(op.basis_l,op.basis_r,zero(op.data))
 Base.eltype(op::Operator) = eltype(op.data)
 Base.eltype(::Type{T}) where {BL,BR,D,T<:Operator{BL,BR,D}} = eltype(D)