diff --git a/freqtrade/exchange/__init__.py b/freqtrade/exchange/__init__.py
index cb63c6b9a..57114a342 100644
--- a/freqtrade/exchange/__init__.py
+++ b/freqtrade/exchange/__init__.py
@@ -9,7 +9,8 @@ from freqtrade.exchange.bitpanda import Bitpanda
 from freqtrade.exchange.bittrex import Bittrex
 from freqtrade.exchange.bybit import Bybit
 from freqtrade.exchange.coinbasepro import Coinbasepro
-from freqtrade.exchange.exchange import (amount_to_precision, available_exchanges, ccxt_exchanges,
+from freqtrade.exchange.exchange import (amount_to_contracts, amount_to_precision,
+                                         available_exchanges, ccxt_exchanges, contracts_to_amount,
                                          date_minus_candles, is_exchange_known_ccxt,
                                          is_exchange_officially_supported, market_is_active,
                                          price_to_precision, timeframe_to_minutes,
diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 44288e696..7d2a2f5c5 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -2892,7 +2892,7 @@ def market_is_active(market: Dict) -> bool:
     return market.get('active', True) is not False
 
 
-def amount_to_contracts(amount: float, contract_size: float) -> float:
+def amount_to_contracts(amount: float, contract_size: Optional[float]) -> float:
     """
     Convert amount to contracts.
     :param amount: amount to convert
@@ -2905,7 +2905,7 @@ def amount_to_contracts(amount: float, contract_size: float) -> float:
         return amount
 
 
-def contracts_to_amount(num_contracts: float, contract_size: float) -> float:
+def contracts_to_amount(num_contracts: float, contract_size: Optional[float]) -> float:
     """
     Takes num-contracts and converts it to contract size
     :param num_contracts: number of contracts
diff --git a/freqtrade/freqtradebot.py b/freqtrade/freqtradebot.py
index bb66303a8..5791a816d 100644
--- a/freqtrade/freqtradebot.py
+++ b/freqtrade/freqtradebot.py
@@ -756,6 +756,7 @@ class FreqtradeBot(LoggingMixin):
                 amount_precision=self.exchange.get_precision_amount(pair),
                 price_precision=self.exchange.get_precision_price(pair),
                 precision_mode=self.exchange.precisionMode,
+                contract_size=self.exchange.get_contract_size(pair),
             )
         else:
             # This is additional buy, we reset fee_open_currency so timeout checking can work
diff --git a/freqtrade/optimize/backtesting.py b/freqtrade/optimize/backtesting.py
index e32eae533..e81698eef 100644
--- a/freqtrade/optimize/backtesting.py
+++ b/freqtrade/optimize/backtesting.py
@@ -24,7 +24,8 @@ from freqtrade.enums import (BacktestState, CandleType, ExitCheckTuple, ExitType
                              TradingMode)
 from freqtrade.exceptions import DependencyException, OperationalException
 from freqtrade.exchange import timeframe_to_minutes, timeframe_to_seconds
-from freqtrade.exchange.exchange import amount_to_precision
+from freqtrade.exchange.exchange import (amount_to_contracts, amount_to_precision,
+                                         contracts_to_amount)
 from freqtrade.mixins import LoggingMixin
 from freqtrade.optimize.backtest_caching import get_strategy_run_id
 from freqtrade.optimize.bt_progress import BTProgress
@@ -823,11 +824,13 @@ class Backtesting:
             self.order_id_counter += 1
             base_currency = self.exchange.get_pair_base_currency(pair)
             amount_p = (stake_amount / propose_rate) * leverage
-            amount = self.exchange._contracts_to_amount(
-                pair, amount_to_precision(
-                    self.exchange._amount_to_contracts(pair, amount_p),
-                    self.exchange.get_precision_amount(pair), self.precision_mode)
-                )
+            contract_size = self.exchange.get_contract_size(pair)
+            precision_amount = self.exchange.get_precision_amount(pair)
+            amount = contracts_to_amount(
+                amount_to_precision(
+                    amount_to_contracts(amount_p, contract_size),
+                    precision_amount, self.precision_mode),
+                contract_size)
             # Backcalculate actual stake amount.
             stake_amount = amount * propose_rate / leverage
 
@@ -859,9 +862,10 @@ class Backtesting:
                     trading_mode=self.trading_mode,
                     leverage=leverage,
                     # interest_rate=interest_rate,
-                    amount_precision=self.exchange.get_precision_amount(pair),
+                    amount_precision=precision_amount,
                     price_precision=self.exchange.get_precision_price(pair),
                     precision_mode=self.precision_mode,
+                    contract_size=contract_size,
                     orders=[],
                 )
 
diff --git a/freqtrade/persistence/trade_model.py b/freqtrade/persistence/trade_model.py
index a46a2dd9f..b25487993 100644
--- a/freqtrade/persistence/trade_model.py
+++ b/freqtrade/persistence/trade_model.py
@@ -15,6 +15,7 @@ from freqtrade.constants import (DATETIME_PRINT_FORMAT, MATH_CLOSE_PREC, NON_OPE
 from freqtrade.enums import ExitType, TradingMode
 from freqtrade.exceptions import DependencyException, OperationalException
 from freqtrade.exchange import amount_to_precision, price_to_precision
+from freqtrade.exchange.exchange import amount_to_contracts, contracts_to_amount
 from freqtrade.leverage import interest
 from freqtrade.persistence.base import _DECL_BASE
 from freqtrade.util import FtPrecise
@@ -624,7 +625,11 @@ class LocalTrade():
             else:
                 logger.warning(
                     f'Got different open_order_id {self.open_order_id} != {order.order_id}')
-            amount_tr = amount_to_precision(self.amount, self.amount_precision, self.precision_mode)
+            amount_tr = contracts_to_amount(
+                amount_to_precision(
+                    amount_to_contracts(self.amount, self.contract_size),
+                    self.amount_precision, self.precision_mode),
+                self.contract_size)
             if isclose(order.safe_amount_after_fee, amount_tr, abs_tol=MATH_CLOSE_PREC):
                 self.close(order.safe_price)
             else: