diff --git a/README.md b/README.md
index 51b2640..65f2b74 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,7 @@ BITCOIND_USER         # RPC username
 BITCOIND_PASS         # RPC password
 BITCOIND_DATADIR      # bitcoind datadir. 'testnet3' will be appended automatically if testnet is used. NEED to finish with '/'. e.g: `/vol/data/`
 INSIGHT_NETWORK [= 'livenet' | 'testnet']
+INSIGHT_PORT          # insight api port
 INSIGHT_DB            # Path where to store insight's internal DB. (defaults to $HOME/.insight)
 INSIGHT_SAFE_CONFIRMATIONS=6  # Nr. of confirmation needed to start caching transaction information   
 INSIGHT_IGNORE_CACHE  # True to ignore cache of spents in transaction, with more than INSIGHT_SAFE_CONFIRMATIONS confirmations. This is useful for tracking double spents for old transactions.