diff --git a/src/BitStringAddresses/occupationnumberfs.jl b/src/BitStringAddresses/occupationnumberfs.jl
index 23292d635..8921b39ef 100644
--- a/src/BitStringAddresses/occupationnumberfs.jl
+++ b/src/BitStringAddresses/occupationnumberfs.jl
@@ -43,12 +43,8 @@ julia> num_particles(ofs)
 6
 ```
 """
-struct OccupationNumberFS{M,T} <: SingleComponentFockAddress{missing,M}
+struct OccupationNumberFS{M,T<:Unsigned} <: SingleComponentFockAddress{missing,M}
     onr::SVector{M,T}
-
-    function OccupationNumberFS(onr::SVector{M,T}) where {M,T<:Unsigned}
-        new{M,T}(onr)
-    end
 end
 
 function OccupationNumberFS{M,T}(args...) where {M,T}