diff --git a/beacon_node/lighthouse_network/src/config.rs b/beacon_node/lighthouse_network/src/config.rs
index a60ca3ce078..d36180f02d4 100644
--- a/beacon_node/lighthouse_network/src/config.rs
+++ b/beacon_node/lighthouse_network/src/config.rs
@@ -128,7 +128,7 @@ pub struct Config {
     /// Whether to subscribe to the EIP-8025 `execution_proof` gossip topic.
     pub enable_execution_proof: bool,
 
-    /// Whether to enable the mplex multiplexer alongside yamux. Enabled by default.
+    /// Whether to enable the mplex multiplexer alongside yamux. Disabled by default.
     pub enable_mplex: bool,
 
     /// Configuration for the outbound rate limiter (requests made by this node).
@@ -369,7 +369,7 @@ impl Default for Config {
             metrics_enabled: false,
             enable_light_client_server: true,
             enable_execution_proof: false,
-            enable_mplex: true,
+            enable_mplex: false,
             outbound_rate_limiter_config: None,
             invalid_block_storage: None,
             inbound_rate_limiter_config: None,
diff --git a/beacon_node/src/cli.rs b/beacon_node/src/cli.rs
index 11a84fb77dd..7355d03b227 100644
--- a/beacon_node/src/cli.rs
+++ b/beacon_node/src/cli.rs
@@ -393,9 +393,9 @@ pub fn cli_app() -> Command {
                 .value_name("BOOLEAN")
                 .action(ArgAction::Set)
                 .num_args(0..=1)
-                .default_value("true")
+                .default_value("false")
                 .default_missing_value("true")
-                .help("Enables the mplex multiplexer alongside yamux. Yamux is preferred when both are available. Enabled by default; set to \"false\" to disable.")
+                .help("Enables the mplex multiplexer alongside yamux. Yamux is preferred when both are available. Disabled by default; set to \"true\" to enable.")
                 .display_order(0)
         )
         .arg(
diff --git a/book/src/help_bn.md b/book/src/help_bn.md
index 9d13116945e..a65601a38d3 100644
--- a/book/src/help_bn.md
+++ b/book/src/help_bn.md
@@ -86,8 +86,8 @@ Options:
           both IPv4 and IPv6. Defaults to `port6`
       --enable-mplex [<BOOLEAN>]
           Enables the mplex multiplexer alongside yamux. Yamux is preferred when
-          both are available. Enabled by default; set to "false" to disable.
-          [default: true]
+          both are available. Disabled by default; set to "true" to enable.
+          [default: false]
       --enable-partial-columns [<BOOLEAN>]
           Enable partial messages for data columns. This can reduce the amount
           of data sent over the network. Enabled by default on Hoodi and
diff --git a/lighthouse/tests/beacon_node.rs b/lighthouse/tests/beacon_node.rs
index 03676372faf..f68b952acfa 100644
--- a/lighthouse/tests/beacon_node.rs
+++ b/lighthouse/tests/beacon_node.rs
@@ -2813,11 +2813,11 @@ fn invalid_block_roots_default_mainnet() {
 }
 
 #[test]
-fn enable_mplex_default() {
+fn disable_mplex_default() {
     CommandLineTest::new()
         .run_with_zero_port()
         .with_config(|config| {
-            assert!(config.network.enable_mplex);
+            assert!(!config.network.enable_mplex);
         })
 }