diff --git a/src/CartBlock.C b/src/CartBlock.C
index 90149c4..766f245 100644
--- a/src/CartBlock.C
+++ b/src/CartBlock.C
@@ -171,10 +171,11 @@ void CartBlock::preprocess(CartGrid* cg)
     for (int n = 0; n < 3; n++) {
         dx[n] = cg->dx[(3 * global_id) + n];
     }
-    dims[0] = cg->ihi[static_cast<ptrdiff_t>(3 * global_id)] -
-              cg->ilo[static_cast<ptrdiff_t>(3 * global_id)] + 1;
-    dims[1] = cg->ihi[(3 * global_id) + 1] - cg->ilo[(3 * global_id) + 1] + 1;
-    dims[2] = cg->ihi[(3 * global_id) + 2] - cg->ilo[(3 * global_id) + 2] + 1;
+    dims[0] = cg->get_ihi((3 * global_id)) - cg->get_ilo((3 * global_id)) + 1;
+    dims[1] =
+        cg->get_ihi((3 * global_id) + 1) - cg->get_ilo((3 * global_id) + 1) + 1;
+    dims[2] =
+        cg->get_ihi((3 * global_id) + 2) - cg->get_ilo((3 * global_id) + 2) + 1;
     nf = cg->nf;
     myid = cg->get_myid();
     donor_frac = cg->donor_frac;
diff --git a/src/CartGrid.h b/src/CartGrid.h
index 4d081c3..3a77ae8 100644
--- a/src/CartGrid.h
+++ b/src/CartGrid.h
@@ -46,10 +46,10 @@ class CartGrid
     int* proc_id{nullptr};
     int* local_id{nullptr};
     int myid{0};
-
-public:
     int* ilo{nullptr};
     int* ihi{nullptr};
+
+public:
     int* dims{nullptr};
     int nf{0};
     double* xlo{nullptr};
@@ -77,6 +77,8 @@ class CartGrid
     int get_local_id(int index) { return local_id[index]; }
     void set_myid(int rank_id) { myid = rank_id; }
     int get_myid() { return myid; }
+    int get_ilo(int index) { return ilo[index]; }
+    int get_ihi(int index) { return ihi[index]; }
 };
 
 #endif /* CARTGRID_H */