diff --git a/wetb/hawc2/htc_extensions.py b/wetb/hawc2/htc_extensions.py
index 7275bbac296df454c0e704b4671b988f0f32d1af..0327673e4aab12e1ee2c4f0a84f03ba30f82d885 100644
--- a/wetb/hawc2/htc_extensions.py
+++ b/wetb/hawc2/htc_extensions.py
@@ -9,8 +9,6 @@ See documentation of HTCFile below
 import os
 
 
-
-
 class HTCDefaults(object):
 
     empty_htc = """begin simulation;
@@ -70,7 +68,7 @@ class HTCDefaults(object):
         for filename, c in zip(filenames, ['u', 'v', 'w']):
             setattr(mann, 'filename_%s' % c, filename)
         for c, n, dim in zip(['u', 'v', 'w'], no_grid_points, box_dimension):
-            setattr(mann, 'box_dim_%s' % c, "%d %.4f" % (n, dim / (n)))
+            setattr(mann, 'box_dim_%s' % c, "%d %.4f" % (n, dim / (n - 1)))
         if dont_scale:
             mann.dont_scale = 1
         else:
diff --git a/wetb/hawc2/tests/test_htc_file.py b/wetb/hawc2/tests/test_htc_file.py
index ed15b9f4d1357df69119ebd498c999be3e5f71be..194b2b59fd81f1af27691d831a5fa81514c6d9c5 100644
--- a/wetb/hawc2/tests/test_htc_file.py
+++ b/wetb/hawc2/tests/test_htc_file.py
@@ -163,8 +163,8 @@ class TestHtcFile(unittest.TestCase):
     filename_v\t./turb/mann_l30.1_ae1.1000_g3.3_h0_16384x32x32_0.366x3.12x3.12_s0102v.turb;
     filename_w\t./turb/mann_l30.1_ae1.1000_g3.3_h0_16384x32x32_0.366x3.12x3.12_s0102w.turb;
     box_dim_u\t16384 0.3662;
-    box_dim_v\t32 3.125;
-    box_dim_w\t32 3.125;"""
+    box_dim_v\t32 3.2258;
+    box_dim_w\t32 3.2258;"""
         for a, b in zip(s.split("\n"), str(htcfile.wind.mann).split("\n")):
             self.assertEqual(a.strip(), b.strip())
         self.assertEqual(htcfile.wind.turb_format[0], 1)
@@ -182,8 +182,8 @@ class TestHtcFile(unittest.TestCase):
   samplefrq\t3;
   time_start\t100;
   nsteps\t60000.0;
-  box_dim_v\t32 3.125;
-  box_dim_w\t32 3.125;
+  box_dim_v\t32 3.2258;
+  box_dim_w\t32 3.2258;
 end turb_export;"""
         for a, b in zip(s.split("\n"), str(htc.wind.turb_export).split("\n")):
             self.assertEqual(a.strip(), b.strip())