diff --git a/sources/boundaries.F90 b/sources/boundaries.F90
index b30c854..7454313 100644
--- a/sources/boundaries.F90
+++ b/sources/boundaries.F90
@@ -1546,7 +1546,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : nh => ncells_half, ng => nghosts
+#endif /* MPI */
     use coordinates, only : faces_gc, faces_dc
     use equations  , only : nv
 #ifdef MPI
@@ -1888,7 +1890,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : nh => ncells_half, ng => nghosts
+#endif /* MPI */
     use coordinates, only : faces_gr
     use equations  , only : nv
 #ifdef MPI
@@ -2638,7 +2642,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : nh => ncells_half, ng => nghosts
+#endif /* MPI */
     use coordinates, only : edges_gc, edges_dc
     use equations  , only : nv
 #ifdef MPI
@@ -3060,7 +3066,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : nh => ncells_half, ng => nghosts
+#endif /* MPI */
     use coordinates, only : edges_gr
     use equations  , only : nv
 #ifdef MPI
@@ -3973,7 +3981,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : ng => nghosts
+#endif /* MPI */
     use coordinates, only : corners_gc, corners_dc
     use equations  , only : nv
 #ifdef MPI
@@ -4349,7 +4359,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : ng => nghosts
+#endif /* MPI */
     use coordinates, only : corners_gr
     use equations  , only : nv
 #ifdef MPI
@@ -4706,7 +4718,9 @@ module boundaries
     use blocks     , only : block_meta, block_data, block_leaf
     use blocks     , only : list_leaf
     use blocks     , only : block_info, pointer_info
+#ifdef MPI
     use coordinates, only : ng => nghosts
+#endif /* MPI */
     use coordinates, only : corners_gp
     use equations  , only : nv
 #ifdef MPI