diff --git a/pastas/plotting/plotly.py b/pastas/plotting/plotly.py
index 9a5fdf19..89a7f663 100644
--- a/pastas/plotting/plotly.py
+++ b/pastas/plotting/plotly.py
@@ -1,5 +1,6 @@
 """This module contains interactive plots for Pastas models.
 """
+
 import numpy as np
 import pandas as pd
 import plotly.graph_objs as go
diff --git a/pastas/plotting/plotutil.py b/pastas/plotting/plotutil.py
index f1fb2db6..be03e7ba 100644
--- a/pastas/plotting/plotutil.py
+++ b/pastas/plotting/plotutil.py
@@ -1,5 +1,6 @@
 """This module contains utility functions for plotting.
 """
+
 from typing import List, Union
 
 import numpy as np