diff --git a/mlair/helpers/filter.py b/mlair/helpers/filter.py
index 2e43c230f3714f7abf06d4c17edfb2303d79442c..d7c7b8e684be5d6b8bee14a984d4c842f8828ded 100644
--- a/mlair/helpers/filter.py
+++ b/mlair/helpers/filter.py
@@ -121,6 +121,7 @@ class FIRFilter:
         result_array = result_array.transpose(*dims)
         return result_array.broadcast_like(xr.DataArray(dims=dims, coords=new_coords))
 
+
 class ClimateFIRFilter(FIRFilter):
     from mlair.plotting.data_insight_plotting import PlotClimateFirFilter
 
diff --git a/test/test_helpers/test_filter.py b/test/test_helpers/test_filter.py
index 7374ecae434a4f2b5a3e9f09df47d1a14b9a0f8a..519a36b3438cafd041cc65c43572fc026eced4dd 100644
--- a/test/test_helpers/test_filter.py
+++ b/test/test_helpers/test_filter.py
@@ -285,7 +285,7 @@ class TestClimateFIRFilter:
         obj = object.__new__(ClimateFIRFilter)
         obj._h = [1, 2, 3]
         obj._filtered = [4, 5, 63]
-        obj._apriori = [10, 11, 12, 13]
+        obj._apriori_list = [10, 11, 12, 13]
         assert obj.filter_coefficients == [1, 2, 3]
         assert obj.filtered_data == [4, 5, 63]
         assert obj.apriori_data == [10, 11, 12, 13]