diff --git a/modules/util/viirs_l1b_l2.py b/modules/util/viirs_l1b_l2.py
index 1f83e0b11a6245bd40f4493844e63e59c94fb4e4..bcfff9da2d230bad1be290e64544d8ca5345cb47 100644
--- a/modules/util/viirs_l1b_l2.py
+++ b/modules/util/viirs_l1b_l2.py
@@ -203,7 +203,7 @@ def run(data_h5f, param_s, train_tiles, valid_tiles, num_keep_x_tiles=8, tile_wi
     i_start = int(num_pixels / 2) - int((num_keep_x_tiles * tile_width) / 2)
     j_start = 0
 
-    num_keep_y_tiles = int(num_lines / tile_width) - 2
+    num_keep_y_tiles = int(num_lines / tile_width) - 3
 
     num_y_valid = int(num_keep_y_tiles * 0.1) + 1
     num_y_train = num_keep_y_tiles - num_y_valid - 1
@@ -226,7 +226,7 @@ def run(data_h5f, param_s, train_tiles, valid_tiles, num_keep_x_tiles=8, tile_wi
                 continue
             train_tiles.append(nda)
 
-    j_start = num_y_train * tile_width + 1*tile_width
+    j_start = num_y_train * tile_width + 2*tile_width
     for j in range(num_y_valid):
         j_a = j_start + j * j_skip
         j_b = j_a + tile_width