diff --git a/freqtrade/fiat_convert.py b/freqtrade/fiat_convert.py
index 6a80b5641..28f00acdf 100644
--- a/freqtrade/fiat_convert.py
+++ b/freqtrade/fiat_convert.py
@@ -92,7 +92,7 @@ class CryptoToFiatConverter(object):
     def _load_cryptomap(self) -> None:
         try:
             coinlistings = self._coinmarketcap.listings()
-            self._cryptomap = dict(map(lambda coin: (coin["symbol"], coin["id"]),
+            self._cryptomap = dict(map(lambda coin: (coin["symbol"], str(coin["id"]),
                                        coinlistings["data"]))
         except ValueError:
             logger.error("Could not load FIAT Cryptocurrency map")