diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 560da8eb2..57a7f2086 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -619,7 +619,10 @@ class Exchange:
         Checks if required startup_candles is more than ohlcv_candle_limit().
         Requires a grace-period of 5 candles - so a startup-period up to 494 is allowed by default.
         """
-        candle_limit = self.ohlcv_candle_limit(timeframe, self._config['candle_type_def'], None)
+
+        candle_limit = self.ohlcv_candle_limit(
+            timeframe, self._config['candle_type_def'],
+            date_minus_candles(timeframe, startup_candles))
         # Require one more candle - to account for the still open candle.
         candle_count = startup_candles + 1
         # Allow 5 calls to the exchange per pair
diff --git a/freqtrade/exchange/okx.py b/freqtrade/exchange/okx.py
index c8324e62e..ad41984e7 100644
--- a/freqtrade/exchange/okx.py
+++ b/freqtrade/exchange/okx.py
@@ -10,7 +10,7 @@ from freqtrade.enums.candletype import CandleType
 from freqtrade.exceptions import DDosProtection, OperationalException, TemporaryError
 from freqtrade.exchange import Exchange
 from freqtrade.exchange.common import retrier
-from freqtrade.exchange.exchange import timeframe_to_minutes
+from freqtrade.exchange.exchange import date_minus_candles
 
 
 logger = logging.getLogger(__name__)
@@ -23,7 +23,7 @@ class Okx(Exchange):
     """
 
     _ft_has: Dict = {
-        "ohlcv_candle_limit": 300,  # Warning, special case with data prior to X months
+        "ohlcv_candle_limit": 100,  # Warning, special case with data prior to X months
         "mark_ohlcv_timeframe": "4h",
         "funding_fee_timeframe": "8h",
     }
@@ -53,15 +53,13 @@ class Okx(Exchange):
         :param since_ms: Candle-type
         :return: Candle limit as integer
         """
-        now = datetime.now(timezone.utc)
-        offset_mins = timeframe_to_minutes(timeframe) * self._ft_has['ohlcv_candle_limit']
-        if since_ms and since_ms < ((now - timedelta(minutes=offset_mins)).timestamp() * 1000):
-            return 100
-        if candle_type not in (CandleType.FUTURES, CandleType.SPOT):
-            return 100
+        if (
+            candle_type in (CandleType.FUTURES, CandleType.SPOT) and
+            (not since_ms or since_ms > (date_minus_candles(timeframe, 300).timestamp() * 1000))
+        ):
+            return 300
 
-        return int(self._ft_has.get('ohlcv_candle_limit_per_timeframe', {}).get(
-            timeframe, self._ft_has.get('ohlcv_candle_limit')))
+        return super().ohlcv_candle_limit(timeframe, candle_type, since_ms)
 
     @retrier
     def additional_exchange_init(self) -> None:
diff --git a/tests/exchange/test_okx.py b/tests/exchange/test_okx.py
index 2804d471a..19c09ad9e 100644
--- a/tests/exchange/test_okx.py
+++ b/tests/exchange/test_okx.py
@@ -20,14 +20,17 @@ def test_okx_ohlcv_candle_limit(default_conf, mocker):
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUTURES) == 300
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.MARK) == 100
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUNDING_RATE) == 100
+
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.SPOT, start_time) == 100
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUTURES, start_time) == 100
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.MARK, start_time) == 100
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUNDING_RATE, start_time) == 100
         one_call = int((datetime.now(timezone.utc) - timedelta(
             minutes=290 * timeframe_to_minutes(timeframe))).timestamp() * 1000)
+
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.SPOT, one_call) == 300
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUTURES, one_call) == 300
+
         one_call = int((datetime.now(timezone.utc) - timedelta(
             minutes=320 * timeframe_to_minutes(timeframe))).timestamp() * 1000)
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.SPOT, one_call) == 100