diff --git a/doc/REST-interface.md b/doc/REST-interface.md
index bf669235e3..7fbb174030 100644
--- a/doc/REST-interface.md
+++ b/doc/REST-interface.md
@@ -3,6 +3,8 @@ Unauthenticated REST Interface
 
 The REST API can be enabled with the `-rest` option.
 
+The interface runs on the same port as the JSON-RPC interface, by default port 8332 for mainnet and port 18332 for testnet.
+
 Supported API
 -------------