diff --git a/chains/chains_mainnet.json b/chains/chains_mainnet.json
index 41b876a2..a1ac7bd0 100644
--- a/chains/chains_mainnet.json
+++ b/chains/chains_mainnet.json
@@ -18,5 +18,9 @@
     {
         "id": "0021",
         "url": "https://${DOMAIN}/geth"
+    },
+    {
+        "id": "0040",
+        "url": "https://${DOMAIN}/harmony"
     }
 ]
\ No newline at end of file