diff --git a/unix/kasmvnc_defaults.yaml b/unix/kasmvnc_defaults.yaml
index 292e93d..3d0551c 100644
--- a/unix/kasmvnc_defaults.yaml
+++ b/unix/kasmvnc_defaults.yaml
@@ -18,6 +18,7 @@ network:
   udp:
     public_ip: auto
     port: auto
+    payload_size: auto
     stun_server: auto
   ssl:
     pem_certificate: /etc/ssl/certs/ssl-cert-snakeoil.pem
diff --git a/unix/vncserver b/unix/vncserver
index ecdec9e..41fc1be 100755
--- a/unix/vncserver
+++ b/unix/vncserver
@@ -2366,6 +2366,24 @@ sub DefineConfigToCLIConversion {
           $value;
         }
     }),
+    KasmVNC::CliOption->new({
+        name => 'udpSize',
+        configKeys => [
+          KasmVNC::ConfigKey->new({
+            name => "network.udp.payload_size",
+            validator => KasmVNC::PatternValidator->new({
+              pattern => qr/^(auto|\d+)$/,
+              errorMessage => "must be 'auto' or an integer"
+            }),
+          })
+        ],
+        isActiveSub => sub {
+          $self = shift;
+
+          my $value = $self->configValue();
+          isPresent($value) && $value ne 'auto';
+        }
+    }),
     KasmVNC::CliOption->new({
         name => 'udpPort',
         configKeys => [