diff --git a/Project.toml b/Project.toml
index 8bb11f2..7f35f22 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "QuantumInputOutput"
 uuid = "18f9eda6-924c-47c7-a881-996695cfd7c6"
-version = "0.4.0"
+version = "0.4.1"
 
 [deps]
 DataInterpolations = "82cc6244-b520-54b8-b5a6-8a565e85f1d0"
diff --git a/src/SLH.jl b/src/SLH.jl
index 210c4fd..34bc2d0 100644
--- a/src/SLH.jl
+++ b/src/SLH.jl
@@ -95,10 +95,17 @@ SLH triple with scattering matrix `S`, Lindblad vector `L`, and Hamiltonian `H`.
 
 See also [`▷`](@ref), [`⊞`](@ref), [`feedback`](@ref)
 """
-struct SLH{N,ST,LT,HT}
-    scattering::SMatrix{N,N,ST}
+struct SLH{N,ST,LT,HT,L}
+    scattering::SMatrix{N,N,ST,L}
     lindblad::SVector{N,LT}
     hamiltonian::HT
+    function SLH{N,ST,LT,HT}(
+        S::SMatrix{N,N,ST,L},
+        lindblad::SVector{N,LT},
+        H::HT,
+    ) where {N,ST,LT,HT,L}
+        return new{N,ST,LT,HT,L}(S, lindblad, H)
+    end
 end
 
 """