diff --git a/content/en/docs/tasks/administer-cluster/sysctl-cluster.md b/content/en/docs/tasks/administer-cluster/sysctl-cluster.md
index f81623982f..910ee9a817 100644
--- a/content/en/docs/tasks/administer-cluster/sysctl-cluster.md
+++ b/content/en/docs/tasks/administer-cluster/sysctl-cluster.md
@@ -60,6 +60,7 @@ The following sysctls are supported in the _safe_ set:
 - `net.ipv4.ip_local_port_range`,
 - `net.ipv4.tcp_syncookies`,
 - `net.ipv4.ping_group_range` (since Kubernetes 1.18).
+- `net.ipv4.ip_unprivileged_port_start` (since Kubernetes 1.22).
 
 {{< note >}}
 The example `net.ipv4.tcp_syncookies` is not namespaced on Linux kernel version 4.4 or lower.