diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index eb842e39a..48e800d35 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -323,7 +323,7 @@ class Exchange:
         asyncio.set_event_loop(loop)
         return loop
 
-    def validate_config(self, config):
+    def validate_config(self, config: Config) -> None:
         # Check if timeframe is available
         self.validate_timeframes(config.get("timeframe"))