diff --git a/freqtrade/exchange/okx.py b/freqtrade/exchange/okx.py
index dbe746a8f..bd401d198 100644
--- a/freqtrade/exchange/okx.py
+++ b/freqtrade/exchange/okx.py
@@ -11,7 +11,7 @@ from freqtrade.exceptions import (
     RetryableOrderError,
     TemporaryError,
 )
-from freqtrade.exchange import Exchange, date_minus_candles
+from freqtrade.exchange import Exchange
 from freqtrade.exchange.common import API_RETRY_COUNT, retrier
 from freqtrade.exchange.exchange_types import CcxtOrder, FtHas
 from freqtrade.misc import safe_value_fallback2
@@ -80,11 +80,6 @@ class Okx(Exchange):
         if candle_type in (CandleType.FUTURES, CandleType.SPOT):
             return 300
 
-        if candle_type in (CandleType.MARK, CandleType.PREMIUMINDEX) and (
-            not since_ms or since_ms > (date_minus_candles(timeframe, 300).timestamp() * 1000)
-        ):
-            return 300
-
         return super().ohlcv_candle_limit(timeframe, candle_type, since_ms)
 
     @retrier
diff --git a/requirements.txt b/requirements.txt
index 86eb0f40d..b8fa5fe5f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ ft-pandas-ta==0.3.16
 ta-lib==0.6.8
 technical==1.5.3
 
-ccxt==4.5.11
+ccxt==4.5.12
 cryptography==46.0.3
 aiohttp==3.13.1
 SQLAlchemy==2.0.44
diff --git a/tests/exchange/test_exchange.py b/tests/exchange/test_exchange.py
index e5fc6f574..7e3caf039 100644
--- a/tests/exchange/test_exchange.py
+++ b/tests/exchange/test_exchange.py
@@ -2176,10 +2176,7 @@ def test_get_historic_ohlcv(default_conf, mocker, caplog, exchange_name, candle_
     since = date_minus_candles("5m", candle_limit)
     ret = exchange.get_historic_ohlcv(pair, "5m", dt_ts(since), candle_type=candle_type)
 
-    if exchange_name == "okx" and candle_type == "mark":
-        expected = 4
-    else:
-        expected = 2
+    expected = 2
     assert exchange._async_get_candle_history.call_count == expected
     # Returns twice the above OHLCV data after truncating the open candle.
     assert len(ret) == expected
diff --git a/tests/exchange/test_okx.py b/tests/exchange/test_okx.py
index a388c2ab1..750afbd40 100644
--- a/tests/exchange/test_okx.py
+++ b/tests/exchange/test_okx.py
@@ -20,7 +20,7 @@ def test_okx_ohlcv_candle_limit(default_conf, mocker):
     for timeframe in timeframes:
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.SPOT) == 300
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUTURES) == 300
-        assert exchange.ohlcv_candle_limit(timeframe, CandleType.MARK) == 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) == 300
@@ -36,7 +36,7 @@ def test_okx_ohlcv_candle_limit(default_conf, mocker):
 
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.SPOT, one_call) == 300
         assert exchange.ohlcv_candle_limit(timeframe, CandleType.FUTURES, one_call) == 300
-        assert exchange.ohlcv_candle_limit(timeframe, CandleType.MARK, one_call) == 300
+        assert exchange.ohlcv_candle_limit(timeframe, CandleType.MARK, one_call) == 100
 
         one_call = int(
             (