diff --git a/freqtrade/persistence.py b/freqtrade/persistence.py
index a541dcbcc..ea34fd5bf 100644
--- a/freqtrade/persistence.py
+++ b/freqtrade/persistence.py
@@ -402,6 +402,8 @@ class Trade(_DECL_BASE):
             return self.fee_open_currency is not None
         elif side == 'sell':
             return self.fee_close_currency is not None
+        else:
+            return False
 
     def _calc_open_trade_price(self) -> float:
         """
diff --git a/tests/test_persistence.py b/tests/test_persistence.py
index 1a42d95fe..5c7686e28 100644
--- a/tests/test_persistence.py
+++ b/tests/test_persistence.py
@@ -913,6 +913,36 @@ def test_update_fee(fee):
     assert trade.fee_close == fee_rate
 
 
+def test_fee_updated(fee):
+    trade = Trade(
+        pair='ETH/BTC',
+        stake_amount=0.001,
+        fee_open=fee.return_value,
+        open_date=arrow.utcnow().shift(hours=-2).datetime,
+        amount=10,
+        fee_close=fee.return_value,
+        exchange='bittrex',
+        open_rate=1,
+        max_rate=1,
+    )
+
+    assert trade.fee_open_currency is None
+    assert not trade.fee_updated('buy')
+    assert not trade.fee_updated('sell')
+    assert not trade.fee_updated('asdf')
+
+    trade.update_fee(0.15, 'BTC', 0.0075, 'buy')
+    assert trade.fee_updated('buy')
+    assert not trade.fee_updated('sell')
+    assert trade.fee_open_currency is not None
+    assert trade.fee_close_currency is None
+
+    trade.update_fee(0.15, 'ABC', 0.0075, 'sell')
+    assert trade.fee_updated('buy')
+    assert trade.fee_updated('sell')
+    assert not trade.fee_updated('asfd')
+
+
 @pytest.mark.usefixtures("init_persistence")
 def test_total_open_trades_stakes(fee):