diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 43ce37051..9b1605a24 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -370,12 +370,13 @@ class Exchange:
         else:
             return DataFrame()
 
-    def _get_contract_size(self, pair: str) -> int:
+    def _get_contract_size(self, pair: str) -> float:
         if self.trading_mode == TradingMode.FUTURES:
             market = self.markets[pair]
-            contract_size = 1
+            contract_size: float = 1.0
             if 'contractSize' in market and market['contractSize'] is not None:
-                contract_size = market['contractSize']
+                # ccxt has contractSize in markets as string
+                contract_size = float(market['contractSize'])
             return contract_size
         else:
             return 1
diff --git a/tests/conftest.py b/tests/conftest.py
index d3836af59..f5c5d5f6e 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -939,7 +939,7 @@ def get_markets():
             'active': True,
             'spot': False,
             'type': 'swap',
-            'contractSize': 0.01,
+            'contractSize': '0.01',
             'precision': {
                 'amount': 8,
                 'price': 8
@@ -1010,7 +1010,8 @@ def get_markets():
             'percentage': True,
             'taker': 0.0006,
             'maker': 0.0002,
-            'contractSize': 10,
+            # TODO-lev: `contractSize` should be numeric - this is an open bug in ccxt.
+            'contractSize': '10',
             'active': True,
             'expiry': None,
             'expiryDatetime': None,
diff --git a/tests/exchange/test_exchange.py b/tests/exchange/test_exchange.py
index bd7b449b2..db273faf7 100644
--- a/tests/exchange/test_exchange.py
+++ b/tests/exchange/test_exchange.py
@@ -484,7 +484,7 @@ def test_get_min_pair_stake_amount(mocker, default_conf) -> None:
     result = exchange.get_min_pair_stake_amount('ETH/BTC', 2, -1, 12.0)
     assert isclose(result, expected_result/12)
 
-    markets["ETH/BTC"]["contractSize"] = 0.01
+    markets["ETH/BTC"]["contractSize"] = '0.01'
     default_conf['trading_mode'] = 'futures'
     default_conf['collateral'] = 'isolated'
     exchange = get_patched_exchange(mocker, default_conf, id="binance")
@@ -497,7 +497,7 @@ def test_get_min_pair_stake_amount(mocker, default_conf) -> None:
     result = exchange.get_min_pair_stake_amount('ETH/BTC', 2, -1)
     assert isclose(result, expected_result * 0.01)
 
-    markets["ETH/BTC"]["contractSize"] = 10
+    markets["ETH/BTC"]["contractSize"] = '10'
     mocker.patch(
         'freqtrade.exchange.Exchange.markets',
         PropertyMock(return_value=markets)
@@ -3697,14 +3697,14 @@ def test__get_contract_size(mocker, default_conf, pair, expected_size, trading_m
         },
         'XLTCUSDT': {
             'symbol': 'XLTCUSDT',
-            'contractSize': 0.01,
+            'contractSize': '0.01',
         },
         'LTC/ETH': {
             'symbol': 'LTC/ETH',
         },
         'ETH/USDT:USDT': {
             'symbol': 'ETH/USDT:USDT',
-            'contractSize': 10,
+            'contractSize': '10',
         }
     })
     exchange = get_patched_exchange(mocker, default_conf, api_mock)
@@ -3857,14 +3857,14 @@ def test__amount_to_contracts(
         },
         'XLTCUSDT': {
             'symbol': 'XLTCUSDT',
-            'contractSize': 0.01,
+            'contractSize': '0.01',
         },
         'LTC/ETH': {
             'symbol': 'LTC/ETH',
         },
         'ETH/USDT:USDT': {
             'symbol': 'ETH/USDT:USDT',
-            'contractSize': 10,
+            'contractSize': '10',
         }
     })
     exchange = get_patched_exchange(mocker, default_conf, api_mock)