diff --git a/freqtrade/plugins/pairlist/VolumePairList.py b/freqtrade/plugins/pairlist/VolumePairList.py
index c2f102777..b5525e950 100644
--- a/freqtrade/plugins/pairlist/VolumePairList.py
+++ b/freqtrade/plugins/pairlist/VolumePairList.py
@@ -62,16 +62,16 @@ class VolumePairList(IPairList):
 
         # get timeframe in minutes and seconds
         self._tf_in_min = timeframe_to_minutes(self._lookback_timeframe)
-        self._tf_in_sec = self._tf_in_min * 60
+        _tf_in_sec = self._tf_in_min * 60
 
         # wether to use range lookback or not
         self._use_range = (self._tf_in_min > 0) & (self._lookback_period > 0)
 
-        if self._use_range & (self._refresh_period < self._tf_in_sec):
+        if self._use_range & (self._refresh_period < _tf_in_sec):
             raise OperationalException(
                 f'Refresh period of {self._refresh_period} seconds is smaller than one '
                 f'timeframe of {self._lookback_timeframe}. Please adjust refresh_period '
-                f'to at least {self._tf_in_sec} and restart the bot.'
+                f'to at least {_tf_in_sec} and restart the bot.'
             )
 
         if (not self._use_range and not (