diff --git a/scilpy/image/operations.py b/scilpy/image/operations.py
index b9c3a195e..37f951696 100644
--- a/scilpy/image/operations.py
+++ b/scilpy/image/operations.py
@@ -1,7 +1,8 @@
 # -*- coding: utf-8 -*-
 
 """
-Utility operations provided for scil_image_math.py and scil_connectivity_math.py
+Utility operations provided for scil_image_math.py
+and scil_connectivity_math.py
 They basically act as wrappers around numpy to avoid installing MRtrix/FSL
 to apply simple operations on nibabel images or numpy arrays.
 """
@@ -511,23 +512,23 @@ def concatenate(input_list, ref_img):
     concatenate: IMGs
         Concatenate a list of 3D and 4D images into a single 4D image.
     """
-    
+
     _validate_imgs_concat(*input_list, ref_img)
     if len(input_list[0].header.get_data_shape()) > 4:
         raise ValueError('Concatenate require 3D or 4D arrays.')
-    
+
     input_data = []
     for img in input_list:
 
         data = img.get_fdata(dtype=np.float64)
-        
+
         if len(img.header.get_data_shape()) == 4:
             data = np.rollaxis(data, 3)
             for i in range(0, len(data)):
                 input_data.append(data[i])
         else:
-            input_data.append(data)   
-        
+            input_data.append(data)
+
         img.uncache()
 
     return np.rollaxis(np.stack(input_data), axis=0, start=4)
diff --git a/scripts/scil_image_math.py b/scripts/scil_image_math.py
index e26ca6b12..766312bea 100755
--- a/scripts/scil_image_math.py
+++ b/scripts/scil_image_math.py
@@ -107,13 +107,14 @@ def main():
             found_ref = True
             break
 
-    # If there's a 4D image, replace the previous 3D image with this one for reference
+    # If there's a 4D image, replace the previous 3D image with
+    #  this one for reference
     for input_arg in args.in_images:
         if not is_float(input_arg):
             ref_img = nib.load(input_arg)
             if len(ref_img.shape) == 4:
                 mask = np.zeros(ref_img.shape)
-                break 
+                break
 
     if not found_ref:
         raise ValueError('Requires at least one nifti image.')