diff --git a/src/toolbox_scs/routines/boz.py b/src/toolbox_scs/routines/boz.py
index bdfeb1e0d76c56491f6c679472211a8d1f5e7aca..5703ce3c1c0d055ec7118ce71eb352de07f70c78 100644
--- a/src/toolbox_scs/routines/boz.py
+++ b/src/toolbox_scs/routines/boz.py
@@ -273,13 +273,13 @@ def _plane_flat_field(p, roi):
     return Z
 
 
-def compute_flat_field_correction(rois, p, plot=False):
+def compute_flat_field_correction(rois, plane, plot=False):
     """Compute the plane field correction on beam rois.
 
     Inputs
     ------
     rois: dictionnary of beam rois['n', '0', 'p']
-    p: plane vector
+    plane: 2 plane vector concatenated
     plot: boolean, True by default, diagnostic plot
 
     Returns
@@ -289,12 +289,12 @@ def compute_flat_field_correction(rois, p, plot=False):
     """
     flat_field = np.ones((128, 512))
 
-    r = 'n'
-    flat_field[rois[r]['yl']:rois[r]['yh'], rois[r]['xl']:rois[r]['xh']] = \
-                       _plane_flat_field(p[:4], rois[r])
-    r = 'p'
-    flat_field[rois[r]['yl']:rois[r]['yh'], rois[r]['xl']:rois[r]['xh']] = \
-                       _plane_flat_field(p[4:], rois[r])
+    r = rois['n']
+    flat_field[r['yl']:r['yh'], r['xl']:r['xh']] = \
+                       _plane_flat_field(plane[:4], r)
+    r = rois['p']
+    flat_field[r['yl']:r['yh'], r['xl']:r['xh']] = \
+                       _plane_flat_field(plane[4:], r)
 
     if plot:
         f, ax = plt.subplots(1, 1, figsize=(6, 2))