diff --git a/freqtrade/data/dataprovider.py b/freqtrade/data/dataprovider.py
index 3ebfd809c..60a058952 100644
--- a/freqtrade/data/dataprovider.py
+++ b/freqtrade/data/dataprovider.py
@@ -9,7 +9,7 @@ from collections import deque
 from datetime import datetime, timezone
 from typing import Any, Dict, List, Optional, Tuple
 
-from pandas import DataFrame, to_timedelta
+from pandas import DataFrame, Timedelta, Timestamp, to_timedelta
 
 from freqtrade.configuration import TimeRange
 from freqtrade.constants import (FULL_DATAFRAME_THRESHOLD, Config, ListPairsWithTimeframes,
@@ -206,9 +206,11 @@ class DataProvider:
         existing_df, _ = self.__producer_pairs_df[producer_name][pair_key]
 
         # CHECK FOR MISSING CANDLES
-        timeframe_delta = to_timedelta(timeframe)  # Convert the timeframe to a timedelta for pandas
-        local_last = existing_df.iloc[-1]['date']  # We want the last date from our copy
-        incoming_first = dataframe.iloc[0]['date']  # We want the first date from the incoming
+        # Convert the timeframe to a timedelta for pandas
+        timeframe_delta: Timedelta = to_timedelta(timeframe)
+        local_last: Timestamp = existing_df.iloc[-1]['date']  # We want the last date from our copy
+        # We want the first date from the incoming
+        incoming_first: Timestamp = dataframe.iloc[0]['date']
 
         # Remove existing candles that are newer than the incoming first candle
         existing_df1 = existing_df[existing_df['date'] < incoming_first]
@@ -221,7 +223,7 @@ class DataProvider:
         # we missed some candles between our data and the incoming
         # so return False and candle_difference.
         if candle_difference > 1:
-            return (False, candle_difference)
+            return (False, int(candle_difference))
         if existing_df1.empty:
             appended_df = dataframe
         else:
diff --git a/tests/data/test_dataprovider.py b/tests/data/test_dataprovider.py
index e0c79d52a..c6b1dcc5a 100644
--- a/tests/data/test_dataprovider.py
+++ b/tests/data/test_dataprovider.py
@@ -437,6 +437,7 @@ def test_dp__add_external_df(default_conf_usdt):
     # Add the same dataframe again - dataframe size shall not change.
     res = dp._add_external_df('ETH/USDT', df, last_analyzed, timeframe, CandleType.SPOT)
     assert res[0] is True
+    assert isinstance(res[1], int)
     assert res[1] == 0
     df, _ = dp.get_producer_df('ETH/USDT', timeframe, CandleType.SPOT)
     assert len(df) == 24
@@ -446,6 +447,7 @@ def test_dp__add_external_df(default_conf_usdt):
 
     res = dp._add_external_df('ETH/USDT', df2, last_analyzed, timeframe, CandleType.SPOT)
     assert res[0] is True
+    assert isinstance(res[1], int)
     assert res[1] == 0
     df, _ = dp.get_producer_df('ETH/USDT', timeframe, CandleType.SPOT)
     assert len(df) == 48
@@ -455,6 +457,7 @@ def test_dp__add_external_df(default_conf_usdt):
 
     res = dp._add_external_df('ETH/USDT', df3, last_analyzed, timeframe, CandleType.SPOT)
     assert res[0] is True
+    assert isinstance(res[1], int)
     assert res[1] == 0
     df, _ = dp.get_producer_df('ETH/USDT', timeframe, CandleType.SPOT)
     # New length = 48 + 12 (since we have a 12 hour offset).
@@ -478,6 +481,7 @@ def test_dp__add_external_df(default_conf_usdt):
     res = dp._add_external_df('ETH/USDT', df4, last_analyzed, timeframe, CandleType.SPOT)
     assert res[0] is False
     # 36 hours - from 2022-01-03 12:00:00+00:00 to 2022-01-05 00:00:00+00:00
+    assert isinstance(res[1], int)
     assert res[1] == 36
     df, _ = dp.get_producer_df('ETH/USDT', timeframe, CandleType.SPOT)
     # New length = 61 + 1
@@ -488,4 +492,5 @@ def test_dp__add_external_df(default_conf_usdt):
     res = dp._add_external_df('ETH/USDT', df4, last_analyzed, timeframe, CandleType.SPOT)
     assert res[0] is False
     # 36 hours - from 2022-01-03 12:00:00+00:00 to 2022-01-05 00:00:00+00:00
+    assert isinstance(res[1], int)
     assert res[1] == 0