diff --git a/freqtrade/optimize/backtesting.py b/freqtrade/optimize/backtesting.py
index 107d13a25..23fe8f86f 100644
--- a/freqtrade/optimize/backtesting.py
+++ b/freqtrade/optimize/backtesting.py
@@ -73,7 +73,7 @@ def get_sell_trade_entry(pair, row, buy_subset, ticker, trade_count_lock, args):
                   open_date=row.date,
                   stake_amount=stake_amount,
                   amount=stake_amount / row.open,
-                  fee=exchange.get_fee()
+                  fee=exchange.get_fee_taker()
                   )
 
     # calculate win/lose forwards from buy point
@@ -113,7 +113,6 @@ def backtest(args) -> DataFrame:
     records = []
     trades = []
     trade_count_lock: dict = {}
-    exchange._API = Bittrex({'key': '', 'secret': ''})
     for pair, pair_data in processed.items():
         pair_data['buy'], pair_data['sell'] = 0, 0
         ticker = populate_sell_trend(populate_buy_trend(pair_data))
@@ -164,13 +163,14 @@ def start(args):
         format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
     )
 
-    exchange._API = Bittrex({'key': '', 'secret': ''})
-
     logger.info('Using config: %s ...', args.config)
     config = misc.load_config(args.config)
     ticker_interval = config.get('ticker_interval', args.ticker_interval)
     logger.info('Using ticker_interval: %s ...', ticker_interval)
-
+    # patch config to no key
+    config['key'] = ''
+    config['secret'] = ''
+    exchange.init(config)
     data = {}
     pairs = config['exchange']['pair_whitelist']
     if args.live: