diff --git a/src/Interpolations/mpvalue.jl b/src/Interpolations/mpvalue.jl
index 050b229e..87c20930 100644
--- a/src/Interpolations/mpvalue.jl
+++ b/src/Interpolations/mpvalue.jl
@@ -1,3 +1,4 @@
+abstract type Interpolation end
 abstract type Kernel <: Interpolation end
 
 #=
@@ -17,6 +18,8 @@ function create_property(::Type{T}, it::Interpolation, mesh::CartesianMesh{dim};
     error("wrong differentiation type, choose `nothing`, `gradient` and `hessian`")
 end
 
+NeighboringNodesType(::Interpolation, ::CartesianMesh{dim}) where {dim} = CartesianIndices{dim, NTuple{dim, UnitRange{Int}}}
+
 """
     MPValue(Vec{dim}, interpolation)
     MPValue(Vec{dim, T}, interpolation)
@@ -73,10 +76,14 @@ end
 
 @inline neighboringnodes(mp::MPValue) = getfield(mp, :indices)[]
 @inline function neighboringnodes(mp::MPValue, grid::Grid)
+    neighboringnodes(mp, get_mesh(grid))
+end
+@inline function neighboringnodes(mp::MPValue, mesh::CartesianMesh)
     inds = neighboringnodes(mp)
-    @boundscheck checkbounds(grid, inds)
+    @boundscheck checkbounds(mesh, inds)
     inds
 end
+# SpGrid always use CartesianMesh
 @inline function neighboringnodes(mp::MPValue, grid::SpGrid)
     inds = neighboringnodes(mp)
     spinds = get_spinds(grid)
diff --git a/src/Tesserae.jl b/src/Tesserae.jl
index 4f1a3b0c..81b47fdf 100644
--- a/src/Tesserae.jl
+++ b/src/Tesserae.jl
@@ -82,8 +82,6 @@ export
     closevtm,
     closepvd
 
-abstract type Interpolation end
-
 include("utils.jl")
 include("mesh.jl")
 include("blockspace.jl")
diff --git a/src/grid.jl b/src/grid.jl
index 750e92be..ae6dc93c 100644
--- a/src/grid.jl
+++ b/src/grid.jl
@@ -12,7 +12,7 @@ spacing_inv(grid::Grid) = spacing_inv(get_mesh(grid))
 # SpGrid #
 ##########
 
-const SpGrid{N, T, NT <: NamedTuple{<: Any, <: Tuple{AbstractMesh, SpArray, Vararg{SpArray}}}, I} = StructArray{T, N, NT, I}
+const SpGrid{N, T, NT <: NamedTuple{<: Any, <: Tuple{CartesianMesh, SpArray, Vararg{SpArray}}}, I} = StructArray{T, N, NT, I}
 
 function check_gridproperty(::Type{GridProp}, ::Type{Vec{dim, T}}) where {GridProp, dim, T}
     V = fieldtype(GridProp, 1)
diff --git a/src/mesh.jl b/src/mesh.jl
index 668554de..bc695439 100644
--- a/src/mesh.jl
+++ b/src/mesh.jl
@@ -137,8 +137,6 @@ CartesianIndices((1:5,))
 end
 @inline EmptyCartesianIndices(::Val{dim}) where {dim} = CartesianIndices(nfill(1:0, Val(dim)))
 
-NeighboringNodesType(::Interpolation, ::CartesianMesh{dim}) where {dim} = CartesianIndices{dim, NTuple{dim, UnitRange{Int}}}
-
 """
     whichcell(x::Vec, mesh::CartesianMesh)