diff --git a/etrago/cluster/gas.py b/etrago/cluster/gas.py
index 05f350e9..b25f64e6 100644
--- a/etrago/cluster/gas.py
+++ b/etrago/cluster/gas.py
@@ -24,6 +24,8 @@
 import os
 
 if "READTHEDOCS" not in os.environ:
+    import logging
+
     from pypsa import Network
     from pypsa.networkclustering import (
         aggregatebuses,
@@ -31,7 +33,6 @@
         busmap_by_kmeans,
     )
     from six import iteritems
-    import logging
     import numpy as np
     import pandas as pd
     import pypsa.io as io