diff --git a/uniswap/constants.py b/uniswap/constants.py
index f041d983..164514c3 100644
--- a/uniswap/constants.py
+++ b/uniswap/constants.py
@@ -12,6 +12,7 @@
     97: "binance_testnet",
     137: "polygon",
     100: "xdai",
+    250: "fantom",
     42161: "arbitrum",
     421611: "arbitrum_testnet",
 }