--- a/src/SbpOperators/volumeops/volume_operator.jl	Fri Sep 13 14:32:05 2024 +0200
+++ b/src/SbpOperators/volumeops/volume_operator.jl	Fri Sep 13 14:47:23 2024 +0200
@@ -6,23 +6,23 @@
 struct VolumeOperator{T,N,M,K} <: LazyTensor{T,1,1}
     inner_stencil::Stencil{T,N}
     closure_stencils::NTuple{M,Stencil{T,K}}
-    size::NTuple{1,Int}
+    size::Int
     parity::Parity
 
-    function VolumeOperator(inner_stencil::Stencil{T,N}, closure_stencils::Tuple{Stencil{T,K}, Vararg{Stencil{T,K}}}, size::NTuple{1,Int}, parity::Parity) where {T,N,K}
+    function VolumeOperator(inner_stencil::Stencil{T,N}, closure_stencils::Tuple{Stencil{T,K}, Vararg{Stencil{T,K}}}, size::Int, parity::Parity) where {T,N,K}
         M = length(closure_stencils)
         return new{T,N,M,K}(inner_stencil, closure_stencils, size, parity)
     end
 end
 
 function VolumeOperator(grid::EquidistantGrid, inner_stencil, closure_stencils, parity)
-    return VolumeOperator(inner_stencil, Tuple(closure_stencils), size(grid), parity)
+    return VolumeOperator(inner_stencil, Tuple(closure_stencils), size(grid,1), parity)
 end # TBD: Remove this function?
 
 closure_size(::VolumeOperator{T,N,M}) where {T,N,M} = M
 
-LazyTensors.range_size(op::VolumeOperator) = op.size
-LazyTensors.domain_size(op::VolumeOperator) = op.size
+LazyTensors.range_size(op::VolumeOperator) = (op.size,)
+LazyTensors.domain_size(op::VolumeOperator) = (op.size,)
 
 function LazyTensors.apply(op::VolumeOperator, v::AbstractVector, i::Index{Lower})
     return @inbounds apply_stencil(op.closure_stencils[Int(i)], v, Int(i))
@@ -33,11 +33,11 @@
 end
 
 function LazyTensors.apply(op::VolumeOperator, v::AbstractVector, i::Index{Upper})
-    return @inbounds Int(op.parity)*apply_stencil_backwards(op.closure_stencils[op.size[1]-Int(i)+1], v, Int(i))
+    return @inbounds Int(op.parity)*apply_stencil_backwards(op.closure_stencils[op.size-Int(i)+1], v, Int(i))
 end
 
 function LazyTensors.apply(op::VolumeOperator, v::AbstractVector, i)
-    r = getregion(i, closure_size(op), op.size[1])
+    r = getregion(i, closure_size(op), op.size)
     return LazyTensors.apply(op, v, Index(i, r))
 end
 # TODO: Move this to LazyTensors when we have the region communication down.

--- a/test/SbpOperators/volumeops/volume_operator_test.jl	Fri Sep 13 14:32:05 2024 +0200
+++ b/test/SbpOperators/volumeops/volume_operator_test.jl	Fri Sep 13 14:47:23 2024 +0200
@@ -17,7 +17,7 @@
     g = equidistant_grid(0.,1., 11)
 
     @testset "Constructors" begin
-        op = VolumeOperator(inner_stencil,closure_stencils,(11,),even)
+        op = VolumeOperator(inner_stencil, closure_stencils, 11, even)
         @test op == VolumeOperator(g,inner_stencil,closure_stencils,even)
         @test op isa LazyTensor{T,1,1} where T
     end