diff --git a/cal_tools/cal_tools/agipdlib.py b/cal_tools/cal_tools/agipdlib.py
index dad5499d4a244dc09ff245aa2d00688e13543155..f9f6d7bd394b30cde7274c78339fb7ca9d19b0e5 100644
--- a/cal_tools/cal_tools/agipdlib.py
+++ b/cal_tools/cal_tools/agipdlib.py
@@ -1100,8 +1100,9 @@ class AgipdCorrections:
             # do actual validity filtering:
             validc, validf = count[valid], first[valid]
             valid_indices = np.concatenate([np.arange(validf[i],
-                                             validf[i]+validc[i]) 
-                                             for i in range(validf.size)], axis=0)
+                                                      validf[i]+validc[i])
+                                            for i in range(validf.size)],
+                                            axis=0)
             self.valid_indices = np.squeeze(valid_indices).astype(np.int32)
 
         elif self.index_v == 1: