diff --git a/validator/src/main.rs b/validator/src/main.rs
index 881f0c3e8e..8b942aefec 100644
--- a/validator/src/main.rs
+++ b/validator/src/main.rs
@@ -1589,7 +1589,7 @@ pub fn main() {
                 .value_name("HOST")
                 .takes_value(true)
                 .validator(solana_net_utils::is_host)
-                .help("IP address to bind the RPC port [default: use --bind-address]"),
+                .help("IP address to bind the RPC port [default: 127.0.0.1 if --private-rpc is present, otherwise use --bind-address]"),
         )
         .arg(
             Arg::with_name("rpc_threads")
@@ -2214,6 +2214,8 @@ pub fn main() {
     let rpc_bind_address = if matches.is_present("rpc_bind_address") {
         solana_net_utils::parse_host(matches.value_of("rpc_bind_address").unwrap())
             .expect("invalid rpc_bind_address")
+    } else if private_rpc {
+        solana_net_utils::parse_host("127.0.0.1").unwrap()
     } else {
         bind_address
     };