diff --git a/freqtrade/persistence.py b/freqtrade/persistence.py
index 79903d66f..e3043089f 100644
--- a/freqtrade/persistence.py
+++ b/freqtrade/persistence.py
@@ -187,8 +187,8 @@ class Trade(_DECL_BASE):
         """
         open_trade_price = self.calc_open_trade_price()
         close_trade_price = self.calc_close_trade_price(
-            rate=Decimal(rate or self.close_rate),
-            fee=Decimal(fee or self.fee)
+            rate=(rate or self.close_rate),
+            fee=(fee or self.fee)
         )
         return float("{0:.8f}".format(close_trade_price - open_trade_price))
 
@@ -206,8 +206,8 @@ class Trade(_DECL_BASE):
 
         open_trade_price = self.calc_open_trade_price()
         close_trade_price = self.calc_close_trade_price(
-            rate=Decimal(rate or self.close_rate),
-            fee=Decimal(fee or self.fee)
+            rate=(rate or self.close_rate),
+            fee=(fee or self.fee)
         )
 
         return float("{0:.8f}".format((close_trade_price / open_trade_price) - 1))
diff --git a/freqtrade/tests/test_persistence.py b/freqtrade/tests/test_persistence.py
index 401de7acb..f6c5318ce 100644
--- a/freqtrade/tests/test_persistence.py
+++ b/freqtrade/tests/test_persistence.py
@@ -271,10 +271,6 @@ def test_calc_profit(limit_buy_order, limit_sell_order):
     # Lower than open rate
     assert trade.calc_profit(rate=0.00000123, fee=0.003) == -0.00089092
 
-    # Only custom fee without sell order applied
-    with pytest.raises(TypeError):
-        trade.calc_profit(fee=0.003)
-
     # Test when we apply a Sell order. Sell higher than open rate @ 0.00001173
     trade.update(limit_sell_order)
     assert trade.calc_profit() == 0.00006217
@@ -299,10 +295,6 @@ def test_calc_profit_percent(limit_buy_order, limit_sell_order):
     # Get percent of profit with a custom rate (Lower than open rate)
     assert trade.calc_profit_percent(rate=0.00000123) == -0.88863827
 
-    # Only custom fee without sell order applied
-    with pytest.raises(TypeError):
-        trade.calc_profit_percent(fee=0.003)
-
     # Test when we apply a Sell order. Sell higher than open rate @ 0.00001173
     trade.update(limit_sell_order)
     assert trade.calc_profit_percent() == 0.06201057