diff --git a/src/bin/vhost_user_net.rs b/src/bin/vhost_user_net.rs
index 520bb0fe8..7d26aeb1c 100644
--- a/src/bin/vhost_user_net.rs
+++ b/src/bin/vhost_user_net.rs
@@ -21,11 +21,7 @@ fn main() {
         .arg(
             Arg::with_name("net-backend")
                 .long("net-backend")
-                .help(
-                    "vhost-user-net backend parameters \
-                     \"ip=<ip_addr>,mask=<net_mask>,sock=<socket_path>,\
-                     num_queues=<number_of_queues>,queue_size=<size_of_each_queue>,tap=<if_name>\"",
-                )
+                .help(vhost_user_net::SYNTAX)
                 .takes_value(true)
                 .min_values(1),
         )
diff --git a/src/main.rs b/src/main.rs
index 4208ab927..d757b0274 100755
--- a/src/main.rs
+++ b/src/main.rs
@@ -235,11 +235,7 @@ fn create_app<'a, 'b>(
         .arg(
             Arg::with_name("net-backend")
                 .long("net-backend")
-                .help(
-                    "vhost-user-net backend parameters \
-                     \"ip=<ip_addr>,mask=<net_mask>,sock=<socket_path>,\
-                     num_queues=<number_of_queues>,queue_size=<size_of_each_queue>,tap=<if_name>\"",
-                )
+                .help(vhost_user_net::SYNTAX)
                 .takes_value(true)
                 .conflicts_with_all(&["block-backend", "kernel"])
                 .min_values(1),
diff --git a/vhost_user_net/src/lib.rs b/vhost_user_net/src/lib.rs
index 1a152b91f..d2518e3a6 100644
--- a/vhost_user_net/src/lib.rs
+++ b/vhost_user_net/src/lib.rs
@@ -77,6 +77,10 @@ pub enum Error {
     OpenTap(vm_virtio::net_util::Error),
 }
 
+pub const SYNTAX: &str = "vhost-user-net backend parameters \
+\"ip=<ip_addr>,mask=<net_mask>,sock=<socket_path>,\
+num_queues=<number_of_queues>,queue_size=<size_of_each_queue>,tap=<if_name>\"";
+
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "vhost_user_net_error: {:?}", self)