diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 67a79178f..6e281b9b2 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -472,7 +472,7 @@ class Exchange(object):
 
         order = self.create_order(pair, ordertype, 'sell', amount, rate, params)
         logger.info('stoploss limit order added for %s. '
-                    'stop price: %s. limit: %s' % (pair, stop_price, rate))
+                    'stop price: %s. limit: %s', pair, stop_price, rate)
         return order
 
     @retrier
diff --git a/freqtrade/tests/exchange/test_exchange.py b/freqtrade/tests/exchange/test_exchange.py
index 123f1fcfd..397326258 100644
--- a/freqtrade/tests/exchange/test_exchange.py
+++ b/freqtrade/tests/exchange/test_exchange.py
@@ -656,7 +656,13 @@ def test_buy_prod(default_conf, mocker, exchange_name):
     with pytest.raises(DependencyException):
         api_mock.create_order = MagicMock(side_effect=ccxt.InvalidOrder("Order not found"))
         exchange = get_patched_exchange(mocker, default_conf, api_mock, id=exchange_name)
-        exchange.buy(pair='ETH/BTC', ordertype=order_type,
+        exchange.buy(pair='ETH/BTC', ordertype='limit',
+                     amount=1, rate=200, time_in_force=time_in_force)
+
+    with pytest.raises(DependencyException):
+        api_mock.create_order = MagicMock(side_effect=ccxt.InvalidOrder("Order not found"))
+        exchange = get_patched_exchange(mocker, default_conf, api_mock, id=exchange_name)
+        exchange.buy(pair='ETH/BTC', ordertype='market',
                      amount=1, rate=200, time_in_force=time_in_force)
 
     with pytest.raises(TemporaryError):