diff --git a/content/k3s/latest/en/installation/single-server/_index.md b/content/k3s/latest/en/installation/single-server/_index.md
index dd44963c528..be1c761eeff 100644
--- a/content/k3s/latest/en/installation/single-server/_index.md
+++ b/content/k3s/latest/en/installation/single-server/_index.md
@@ -211,6 +211,10 @@ The following information on server options is also available through `k3s serve
 
     (agent) Override default flannel interface
 
+* `--flannel-backend` _value_
+
+    (agent) Specify the flannel backend you would like to use: vxlan (default), ipsec, or wireguard
+
 * `--container-runtime-endpoint` _value_
 
     (agent) Disable embedded containerd and use alternative CRI implementation
@@ -280,6 +284,10 @@ The following information on agent options is also available through `k3s agent
 
     (agent) Override default flannel interface
 
+* `--flannel-backend` _value_
+
+    (agent) Specify the flannel backend you would like to use: vxlan (default), ipsec, or wireguard
+
 * `--node-name` _value_
 
     (agent) Node name [$`K3S_NODE_NAME`]