diff --git a/src/atlas/array/helpers/ArraySlicer.h b/src/atlas/array/helpers/ArraySlicer.h
index ad3bfd730..2e37ebd4e 100644
--- a/src/atlas/array/helpers/ArraySlicer.h
+++ b/src/atlas/array/helpers/ArraySlicer.h
@@ -149,37 +149,37 @@ class ArraySlicer {
     };
 
     template <typename Int>
-    static int offset_part( View& view, int& i_view, Int idx ) {
+    static idx_t offset_part( View& view, int& i_view, Int idx ) {
         return idx * view.stride( i_view++ );
     }
 
-    static int offset_part( View& view, int& i_view, Range range ) { return range.start() * view.stride( i_view++ ); }
+    static idx_t offset_part( View& view, int& i_view, Range range ) { return range.start() * view.stride( i_view++ ); }
 
-    static int offset_part( View& view, int& i_view, RangeAll range ) {
+    static idx_t offset_part( View& view, int& i_view, RangeAll range ) {
         return range.start() * view.stride( i_view++ );
     }
 
-    static int offset_part( View& view, int& i_view, RangeTo range ) { return range.start() * view.stride( i_view++ ); }
+    static idx_t offset_part( View& view, int& i_view, RangeTo range ) { return range.start() * view.stride( i_view++ ); }
 
-    static int offset_part( View& view, int& i_view, RangeFrom range ) {
+    static idx_t offset_part( View& view, int& i_view, RangeFrom range ) {
         return range.start() * view.stride( i_view++ );
     }
 
-    static int offset_part( View&, int& /*i_view*/, RangeDummy ) { return 0; }
+    static idx_t offset_part( View&, int& /*i_view*/, RangeDummy ) { return 0; }
 
     template <int Dim, typename Int, typename... Ints>
-    static int offset_remaining( View& view, int& i_view, const Int idx, const Ints... next_idx ) {
-        const int p = offset_part( view, i_view, idx );
+    static idx_t offset_remaining( View& view, int& i_view, const Int idx, const Ints... next_idx ) {
+        const idx_t p = offset_part( view, i_view, idx );
         return p + offset_remaining<Dim + 1>( view, i_view, next_idx... );
     }
 
     template <int Dim, typename Int>
-    static int offset_remaining( View& view, int& i_view, const Int last_idx ) {
+    static idx_t offset_remaining( View& view, int& i_view, const Int last_idx ) {
         return offset_part( view, i_view, last_idx );
     }
 
     template <typename... Args>
-    static int offset( View& view, const Args... args ) {
+    static idx_t offset( View& view, const Args... args ) {
         int i_view( 0 );
         return offset_remaining<0>( view, i_view, args... );
     }
diff --git a/src/tests/functionspace/test_structuredcolumns.cc b/src/tests/functionspace/test_structuredcolumns.cc
index 165153d96..4a2d066dc 100644
--- a/src/tests/functionspace/test_structuredcolumns.cc
+++ b/src/tests/functionspace/test_structuredcolumns.cc
@@ -382,8 +382,8 @@ CASE( "test_functionspace_StructuredColumns halo exchange adjoint test 1" ) {
 
     // Field setup  values 1 in interior and zeros in halos.
     auto view1   = atlas::array::make_view<long, 2>( fieldInit );
-    auto i_index = atlas::array::make_view<int, 1>( fs.index_i() );
-    auto j_index = atlas::array::make_view<int, 1>( fs.index_j() );
+    auto i_index = atlas::array::make_view<atlas::idx_t, 1>( fs.index_i() );
+    auto j_index = atlas::array::make_view<atlas::idx_t, 1>( fs.index_j() );
     for ( atlas::idx_t jn = 0; jn < fs.sizeOwned(); ++jn ) {
         for ( atlas::idx_t jl = 0; jl < fieldInit.levels(); ++jl ) {
             view1( jn, jl ) = 1;
diff --git a/src/tests/functionspace/test_structuredcolumns_biperiodic.cc b/src/tests/functionspace/test_structuredcolumns_biperiodic.cc
index 3831eba99..dc7c23051 100644
--- a/src/tests/functionspace/test_structuredcolumns_biperiodic.cc
+++ b/src/tests/functionspace/test_structuredcolumns_biperiodic.cc
@@ -90,7 +90,7 @@ CASE( "biperiodic_latlon" ) {
     };
 
     auto gv = atlas::array::make_view<atlas::gidx_t, 1>( fs.global_index() );
-    auto pv = atlas::array::make_view<atlas::idx_t, 1>( fs.partition() );
+    auto pv = atlas::array::make_view<int, 1>( fs.partition() );
 
     for ( int j = fs.j_begin_halo(); j < fs.j_end_halo(); j++ ) {
         for ( int i = fs.i_begin_halo( j ); i < fs.i_end_halo( j ); i++ ) {
diff --git a/src/tests/functionspace/test_structuredcolumns_haloexchange.cc b/src/tests/functionspace/test_structuredcolumns_haloexchange.cc
index 8a2862d45..6c31217a1 100644
--- a/src/tests/functionspace/test_structuredcolumns_haloexchange.cc
+++ b/src/tests/functionspace/test_structuredcolumns_haloexchange.cc
@@ -38,14 +38,14 @@ namespace test {
 atlas::FieldSet getIJ( const atlas::functionspace::StructuredColumns& fs ) {
     atlas::FieldSet ij;
 
-    auto vi0 = atlas::array::make_view<int, 1>( fs.index_i() );
-    auto vj0 = atlas::array::make_view<int, 1>( fs.index_j() );
+    auto vi0 = atlas::array::make_view<atlas::idx_t, 1>( fs.index_i() );
+    auto vj0 = atlas::array::make_view<atlas::idx_t, 1>( fs.index_j() );
 
-    auto fi = fs.createField<int>();
-    auto fj = fs.createField<int>();
+    auto fi = fs.createField<atlas::idx_t>();
+    auto fj = fs.createField<atlas::idx_t>();
 
-    auto vi1 = atlas::array::make_view<int, 1>( fi );
-    auto vj1 = atlas::array::make_view<int, 1>( fj );
+    auto vi1 = atlas::array::make_view<atlas::idx_t, 1>( fi );
+    auto vj1 = atlas::array::make_view<atlas::idx_t, 1>( fj );
 
     for ( int i = 0; i < fs.size(); i++ ) {
         vi1( i ) = vi0( i );
diff --git a/src/tests/grid/test_distribution_regular_bands.cc b/src/tests/grid/test_distribution_regular_bands.cc
index 23c0a5f61..d69c35d58 100644
--- a/src/tests/grid/test_distribution_regular_bands.cc
+++ b/src/tests/grid/test_distribution_regular_bands.cc
@@ -120,10 +120,10 @@ CASE( "test_regular_bands" ) {
                 EXPECT_EQ( fs_regularbands.size(), fs_checkerboard.size() );
                 EXPECT_EQ( fs_regularbands.sizeOwned(), fs_checkerboard.sizeOwned() );
 
-                auto i1 = array::make_view<int, 1>( ij1[0] );
-                auto j1 = array::make_view<int, 1>( ij1[1] );
-                auto i2 = array::make_view<int, 1>( ij2[0] );
-                auto j2 = array::make_view<int, 1>( ij2[1] );
+                auto i1 = array::make_view<idx_t, 1>( ij1[0] );
+                auto j1 = array::make_view<idx_t, 1>( ij1[1] );
+                auto i2 = array::make_view<idx_t, 1>( ij2[0] );
+                auto j2 = array::make_view<idx_t, 1>( ij2[1] );
 
                 for ( int k = 0; k < fs_checkerboard.sizeOwned(); k++ ) {
                     EXPECT_EQ( i1[k], i2[k] );