diff --git a/AMSS_NCKU_source/Parallel.C b/AMSS_NCKU_source/Parallel.C
index 713a6a7..e1d5a35 100644
--- a/AMSS_NCKU_source/Parallel.C
+++ b/AMSS_NCKU_source/Parallel.C
@@ -313,7 +313,7 @@ MyList<Block> *Parallel::distribute(MyList<Patch> *PatchLIST, int cpusize, int i
 
   int split_size, min_size, block_size = 0;
 
-  int min_width = 2 * Mymax(ghost_width, buffer_width);
+  int min_width = Mymax(2 * ghost_width + 2, buffer_width + 2);
   int nxyz[dim], mmin_width[dim], min_shape[dim];
 
   MyList<Patch> *PLi = PatchLIST;
@@ -641,7 +641,7 @@ MyList<Block> *Parallel::distribute(MyList<Patch> *PatchLIST, int cpusize, int i
 
   int split_size, min_size, block_size = 0;
 
-  int min_width = 2 * Mymax(ghost_width, buffer_width);
+  int min_width = Mymax(2 * ghost_width + 2, buffer_width + 2);
   int nxyz[dim], mmin_width[dim], min_shape[dim];
 
   MyList<Patch> *PLi = PatchLIST;