diff --git a/message_ix_models/tests/model/water/test_utils.py b/message_ix_models/tests/model/water/test_utils.py
index 051e6976d6..d12fa59880 100644
--- a/message_ix_models/tests/model/water/test_utils.py
+++ b/message_ix_models/tests/model/water/test_utils.py
@@ -2,15 +2,15 @@
 
 import pandas as pd
 import xarray as xr
+from sdmx.model.v21 import Code
 
+from message_ix_models import Context
 from message_ix_models.model.water.utils import (
     add_commodity_and_level,
     map_add_on,
     map_yv_ya_lt,
     read_config,
 )
-from message_ix_models import Context
-from sdmx.model.v21 import Code
 
 
 def test_read_config():
diff --git a/message_ix_models/tests/model/water/test_water_supply.py b/message_ix_models/tests/model/water/test_water_supply.py
index 77249925af..134cd870c4 100644
--- a/message_ix_models/tests/model/water/test_water_supply.py
+++ b/message_ix_models/tests/model/water/test_water_supply.py
@@ -97,7 +97,8 @@ def test_add_water_supply():
     with patch(
         "message_ix_models.util.private_data_path", return_value="path/to/file"
     ), patch("pandas.read_csv", return_value=df_node), patch(
-        "message_ix_models.model.water.water_supply.map_basin_region_wat", return_value=df_sw  # Adjust this import
+        "message_ix_models.model.water.water_supply.map_basin_region_wat",
+        return_value=df_sw  # Adjust this import
     ):
         # Call the function to be tested
         result = add_water_supply(context)
@@ -135,7 +136,8 @@ def test_add_e_flow():
 
     # Mock the function 'read_water_availability' to return the mocked DataFrame
     with patch(
-        "message_ix_models.model.water.demands.read_water_availability", return_value=(df_sw, df_sw)
+        "message_ix_models.model.water.demands.read_water_availability",
+        return_value=(df_sw, df_sw)
     ), patch(
         "message_ix_models.util.private_data_path", return_value="path/to/file"
     ), patch(