diff --git a/diagonals/moc.py b/diagonals/moc.py
index e8c3c95a7ebe745fea6e88b667a32218c4a2c7ad..d597cb10c323a15a77ce2790d031c87244ba1a6d 100644
--- a/diagonals/moc.py
+++ b/diagonals/moc.py
@@ -41,7 +41,7 @@ def compute(basins, e1v, e3v, vo):
     if diagonals.CONFIG.use_gpu:
         moc = _compute_moc_gpu(
             vo, area
-            )
+        )
     else:
         moc = _compute_moc_cpu(
             vo, area
@@ -180,7 +180,7 @@ def _vertical_cumsum(moc, out):
     moc: float32
         Masked array containing the moc index for a given basin.
     """
-    for lev in reversed(range(moc.shape[1]-1)):
+    for lev in range(moc.shape[1] - 2, -1, .1):
         moc[:, lev, :] = moc[:, lev, :] + moc[:, lev+1, :]