diff --git a/share/examples/bitcoin.conf b/share/examples/bitcoin.conf
index 1b768924ed5..a8dfc2735d9 100644
--- a/share/examples/bitcoin.conf
+++ b/share/examples/bitcoin.conf
@@ -290,7 +290,8 @@
 
 # Listen for connections on <port> (default: 8333, testnet3: 18333,
 # testnet4: 48333, signet: 38333, regtest: 18444). Not relevant for
-# I2P (see doc/i2p.md).
+# I2P (see doc/i2p.md). If set to a value x, the default onion
+# listening port will be set to x+1.
 #port=<port>
 
 # Connect through SOCKS5 proxy, set -noproxy to disable (default:
@@ -697,9 +698,12 @@
 # Options for mainnet
 [main]
 
-# Options for testnet
+# Options for testnet3
 [test]
 
+# Options for testnet4
+[testnet4]
+
 # Options for signet
 [signet]