diff --git a/README.md b/README.md
index 6bb80b7..1d8dcea 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,7 @@ this query port may work instead. (defaults to protocol default port)
 * **attemptTimeout**: number - Milliseconds allowed for an entire query attempt. This timeout is not commonly hit,
  as the socketTimeout typically fires first. (default 10000)
 * **givenPortOnly**: boolean - Only attempt to query server on given port. (default false)
+* **ipFamily**: number - IP family/version returned when looking up hostnames via DNS, can be 0 (IPv4 and IPv6), 4 (IPv4 only) or 6 (IPv6 only). (default 0)
 * **debug**: boolean - Enables massive amounts of debug logging to stdout. (default false)
 * **requestRules**: boolean - Valve games only. Additional 'rules' may be fetched into the `raw` field. (default false)