diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..79f3e46
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,38 @@
+name: CI
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+jobs:
+  test:
+    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - '1'
+        os:
+          - ubuntu-latest
+          - macos-latest
+        arch:
+          - x64
+        exclude:
+          - os: macos-latest
+            arch: x64
+        include:
+          - os: macos-latest
+            arch: aarch64
+            version: '1'
+          - os: ubuntu-latest
+            arch: x64
+            version: 'pre'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v2
+        with:
+          version: ${{ matrix.version }}
+      - uses: julia-actions/cache@v2
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index e77c2b9..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-language: julia
-osx_image: xcode11.4
-notifications:
-  email: false
-os:
-  - linux
-  - osx
-julia:
-  - 1
-  - nightly
-matrix:
-  allow_failures:
-    - julia: nightly
diff --git a/src/core/distmultivec.jl b/src/core/distmultivec.jl
index a97e2c7..b9dfd2c 100644
--- a/src/core/distmultivec.jl
+++ b/src/core/distmultivec.jl
@@ -1,5 +1,6 @@
 mutable struct DistMultiVec{T} <: ElementalMatrix{T}
     obj::Ptr{Cvoid}
+    grid::Grid # keep the grid around to avoid that it's freed before the matrix
 end
 
 for (elty, ext) in ((:ElInt, :i),
@@ -16,24 +17,16 @@ for (elty, ext) in ((:ElInt, :i),
             return nothing
         end
 
-        function DistMultiVec(::Type{$elty}, cm::ElComm = MPI.CommWorld[])
+        function DistMultiVec(::Type{$elty}, grid::Grid = DefaultGrid[])
             obj = Ref{Ptr{Cvoid}}(C_NULL)
             ElError(ccall(($(string("ElDistMultiVecCreate_", ext)), libEl), Cuint,
-                (Ref{Ptr{Cvoid}}, ElComm),
-                obj, cm))
-            A = DistMultiVec{$elty}(obj[])
+                (Ref{Ptr{Cvoid}}, Ptr{Cvoid}),
+                obj, grid.obj))
+            A = DistMultiVec{$elty}(obj[], grid)
             finalizer(destroy, A)
             return A
         end
 
-        function comm(A::DistMultiVec{$elty})
-            cm = Ref{ElComm}()
-            ElError(ccall(($(string("ElDistMultiVecComm_", ext)), libEl), Cuint,
-                (Ptr{Cvoid}, Ref{ElComm}),
-                A.obj, cm))
-            return cm[]
-        end
-
         function get(x::DistMultiVec{$elty}, i::Integer = size(x, 1), j::Integer = 1)
             v = Ref{$elty}()
             ElError(ccall(($(string("ElDistMultiVecGet_", ext)), libEl), Cuint,
@@ -117,8 +110,8 @@ end
 
 getindex(x::DistMultiVec, i, j) = get(x, i, j)
 
-function similar(::DistMultiVec, ::Type{T}, sz::Dims, cm::ElComm = MPI.CommWorld[]) where {T}
-    A = DistMultiVec(T, cm)
+function similar(::DistMultiVec, ::Type{T}, sz::Dims, grid::Grid = DefaultGrid[]) where {T}
+    A = DistMultiVec(T, grid)
     resize!(A, sz...)
     return A
 end
diff --git a/src/core/distsparsematrix.jl b/src/core/distsparsematrix.jl
index 131b210..d2f732c 100644
--- a/src/core/distsparsematrix.jl
+++ b/src/core/distsparsematrix.jl
@@ -1,5 +1,6 @@
 mutable struct DistSparseMatrix{T} <: ElementalMatrix{T}
     obj::Ptr{Cvoid}
+    grid::Grid # keep the grid around to avoid that it's freed before the matrix
 end
 
 for (elty, ext) in ((:ElInt, :i),
@@ -16,24 +17,16 @@ for (elty, ext) in ((:ElInt, :i),
             return nothing
         end
 
-        function DistSparseMatrix(::Type{$elty}, comm::ElComm = MPI.CommWorld[])
+        function DistSparseMatrix(::Type{$elty}, grid::Grid = DefaultGrid[])
             obj = Ref{Ptr{Cvoid}}(C_NULL)
             ElError(ccall(($(string("ElDistSparseMatrixCreate_", ext)), libEl), Cuint,
-                (Ref{Ptr{Cvoid}}, ElComm),
-                obj, comm))
-            A = DistSparseMatrix{$elty}(obj[])
+                (Ref{Ptr{Cvoid}}, Ptr{Cvoid}),
+                obj, grid.obj))
+            A = DistSparseMatrix{$elty}(obj[], grid)
             finalizer(destroy, A)
             return A
         end
 
-        function comm(A::DistSparseMatrix{$elty})
-            cm = Ref{ElComm}()
-            ElError(ccall(($(string("ElDistSparseMatrixComm_", ext)), libEl), Cuint,
-                (Ptr{Cvoid}, Ref{ElComm}),
-                A.obj, cm))
-            return cm[]
-        end
-
         function globalRow(A::DistSparseMatrix{$elty}, iLoc::Integer)
             i = Ref{ElInt}(0)
             ElError(ccall(($(string("ElDistSparseMatrixGlobalRow_", ext)), libEl), Cuint,
@@ -112,8 +105,8 @@ for (elty, ext) in ((:ElInt, :i),
 end
 
 # The other constructors don't have a version with dimensions. Should they, or should this one go?
-function DistSparseMatrix(::Type{T}, m::Integer, n::Integer, comm::ElComm = MPI.CommWorld[]) where {T}
-    A = DistSparseMatrix(T, comm)
+function DistSparseMatrix(::Type{T}, m::Integer, n::Integer, grid::Grid = DefaultGrid[]) where {T}
+    A = DistSparseMatrix(T, grid)
     resize!(A, m, n)
     return A
 end
diff --git a/src/lapack_like/euclidean_min.jl b/src/lapack_like/euclidean_min.jl
index 9550f1a..90d1cce 100644
--- a/src/lapack_like/euclidean_min.jl
+++ b/src/lapack_like/euclidean_min.jl
@@ -23,7 +23,7 @@ function leastSquares(A::DistMatrix{T}, B::DistMatrix{T};
 end
 function leastSquares(A::DistSparseMatrix{T}, B::DistMultiVec{T};
     orientation::Orientation = NORMAL) where {T}
-    X = DistMultiVec(T, comm(A))
+    X = DistMultiVec(T, A.grid)
     return leastSquares!(A, B, X, orientation = orientation)
 end
 
@@ -49,7 +49,7 @@ function bpdn(A::DistMatrix{T}, B::DistMatrix{T}, lambda::T) where {T}
     return bpdn!(A, B, lambda, X)
 end
 function bpdn(A::DistSparseMatrix{T}, B::DistMultiVec{T}, lambda) where {T}
-    X = DistMultiVec(T, comm(A))
+    X = DistMultiVec(T, A.grid)
     return bpdn!(A, B, lambda, X)
 end
 
@@ -78,6 +78,6 @@ function ridge(A::DistMatrix{T}, B::DistMatrix{T}, gamma::T; ka...) where {T}
     return ridge!(A, B, gamma, X; ka...)
 end
 function ridge(A::DistSparseMatrix{T}, B::DistMultiVec{T}, gamma::T; ka...) where {T}
-    X = DistMultiVec(T, comm(A))
+    X = DistMultiVec(T, A.grid)
     return ridge!(A, B, gamma, X; ka...)
 end
\ No newline at end of file
diff --git a/src/optimization/models.jl b/src/optimization/models.jl
index 96b504c..37b2bcb 100644
--- a/src/optimization/models.jl
+++ b/src/optimization/models.jl
@@ -33,11 +33,11 @@ function lav(A::DistMatrix{T}, b::DistMatrix{T}) where {T<:Union{Float32,Float64
     return lav!(A, b, x)
 end
 function lav(A::DistSparseMatrix{T}, b::DistMultiVec{T}) where {T<:Union{Float32,Float64}}
-    x = DistMultiVec(T, comm(A))
+    x = DistMultiVec(T, A.grid)
     return lav!(A, b, x)
 end
 
 function lav(A::DistSparseMatrix{T}, b::DistMultiVec{T}, ctrl::LPAffineCtrl{T}) where {T<:Union{Float32,Float64}}
-    x = DistMultiVec(T, comm(A))
+    x = DistMultiVec(T, A.grid)
     return lav!(A, b, x, ctrl)
 end