diff --git a/pystencils/boundaries/createindexlist.py b/pystencils/boundaries/createindexlist.py
index 51bd5464f89b80c1ed272f1b4b0a932e46095863..0e23b93ee6646c4aa1519df31923dbef97b8cecc 100644
--- a/pystencils/boundaries/createindexlist.py
+++ b/pystencils/boundaries/createindexlist.py
@@ -30,15 +30,15 @@ direction_member_name = "dir"
 
 def numpy_data_type_for_boundary_object(boundary_object, dim):
     coordinate_names = boundary_index_array_coordinate_names[:dim]
-    return np.dtype([(name, np.int32) for name in coordinate_names]
-                    + [(direction_member_name, np.int32)]
+    return np.dtype([(name, np.int64) for name in coordinate_names]
+                    + [(direction_member_name, np.int64)]
                     + [(i[0], i[1].numpy_dtype) for i in boundary_object.additional_data], align=True)
 
 
 def _create_boundary_neighbor_index_list_python(flag_field_arr, nr_of_ghost_layers, boundary_mask,
                                                 fluid_mask, stencil, single_link):
     coordinate_names = boundary_index_array_coordinate_names[:len(flag_field_arr.shape)]
-    index_arr_dtype = np.dtype([(name, np.int32) for name in coordinate_names] + [(direction_member_name, np.int32)])
+    index_arr_dtype = np.dtype([(name, np.int64) for name in coordinate_names] + [(direction_member_name, np.int64)])
 
     result = []
     gl = nr_of_ghost_layers
@@ -59,7 +59,7 @@ def _create_boundary_neighbor_index_list_python(flag_field_arr, nr_of_ghost_laye
 def _create_boundary_cell_index_list_python(flag_field_arr, boundary_mask,
                                             fluid_mask, stencil, single_link):
     coordinate_names = boundary_index_array_coordinate_names[:len(flag_field_arr.shape)]
-    index_arr_dtype = np.dtype([(name, np.int32) for name in coordinate_names] + [(direction_member_name, np.int32)])
+    index_arr_dtype = np.dtype([(name, np.int64) for name in coordinate_names] + [(direction_member_name, np.int64)])
 
     result = []
     for cell in itertools.product(*reversed([range(0, i) for i in flag_field_arr.shape])):
@@ -96,9 +96,9 @@ def create_boundary_index_list(flag_field, stencil, boundary_mask, fluid_mask,
     """
     dim = len(flag_field.shape)
     coordinate_names = boundary_index_array_coordinate_names[:dim]
-    index_arr_dtype = np.dtype([(name, np.int32) for name in coordinate_names] + [(direction_member_name, np.int32)])
+    index_arr_dtype = np.dtype([(name, np.int64) for name in coordinate_names] + [(direction_member_name, np.int64)])
 
-    stencil = np.array(stencil, dtype=np.int32)
+    stencil = np.array(stencil, dtype=np.int64)
     args = (flag_field, nr_of_ghost_layers, boundary_mask, fluid_mask, stencil, single_link)
     args_no_gl = (flag_field, boundary_mask, fluid_mask, stencil, single_link)