diff --git a/Cargo.lock b/Cargo.lock
index 9d7cee34c7c64..82bd2fd53e543 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3860,7 +3860,6 @@ dependencies = [
  "libp2p-kad",
  "libp2p-mdns",
  "libp2p-metrics",
- "libp2p-mplex",
  "libp2p-noise",
  "libp2p-ping",
  "libp2p-quic",
@@ -4044,24 +4043,6 @@ dependencies = [
  "prometheus-client",
 ]
 
-[[package]]
-name = "libp2p-mplex"
-version = "0.39.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d34780b514b159e6f3fd70ba3e72664ec89da28dca2d1e7856ee55e2c7031ba"
-dependencies = [
- "asynchronous-codec",
- "bytes",
- "futures",
- "libp2p-core",
- "log",
- "nohash-hasher",
- "parking_lot 0.12.1",
- "rand 0.8.5",
- "smallvec",
- "unsigned-varint",
-]
-
 [[package]]
 name = "libp2p-noise"
 version = "0.42.0"
diff --git a/client/network/Cargo.toml b/client/network/Cargo.toml
index dab754cf44d6e..de4c4c14a2587 100644
--- a/client/network/Cargo.toml
+++ b/client/network/Cargo.toml
@@ -25,7 +25,7 @@ fnv = "1.0.6"
 futures = "0.3.21"
 futures-timer = "3.0.2"
 ip_network = "0.4.1"
-libp2p = { version = "0.51.3", features = ["dns", "identify", "kad", "macros", "mdns", "mplex", "noise", "ping", "tcp",  "tokio", "yamux", "websocket", "request-response"] }
+libp2p = { version = "0.51.3", features = ["dns", "identify", "kad", "macros", "mdns", "noise", "ping", "tcp",  "tokio", "yamux", "websocket", "request-response"] }
 linked_hash_set = "0.1.3"
 log = "0.4.17"
 lru = "0.8.1"
diff --git a/client/network/README.md b/client/network/README.md
index b9c0e028ffe77..cad46d059092c 100644
--- a/client/network/README.md
+++ b/client/network/README.md
@@ -66,8 +66,6 @@ negotiated and applied. The exact handshake protocol is experimental and is subj
 
 The following multiplexing protocols are supported:
 
-- [Mplex](https://github.com/libp2p/specs/tree/master/mplex). Support for mplex will likely
-be deprecated in the future.
 - [Yamux](https://github.com/hashicorp/yamux/blob/master/spec.md).
 
 ## Substreams
diff --git a/client/network/src/lib.rs b/client/network/src/lib.rs
index f29eb69ade64e..79023923e8b05 100644
--- a/client/network/src/lib.rs
+++ b/client/network/src/lib.rs
@@ -87,8 +87,6 @@
 //!
 //! The following multiplexing protocols are supported:
 //!
-//! - [Mplex](https://github.com/libp2p/specs/tree/master/mplex). Support for mplex will likely
-//! be deprecated in the future.
 //! - [Yamux](https://github.com/hashicorp/yamux/blob/master/spec.md).
 //!
 //! ## Substreams
diff --git a/client/network/src/transport.rs b/client/network/src/transport.rs
index 619961dd0b4fc..e20121154cfcd 100644
--- a/client/network/src/transport.rs
+++ b/client/network/src/transport.rs
@@ -19,12 +19,11 @@
 use either::Either;
 use libp2p::{
 	core::{
-		self,
 		muxing::StreamMuxerBox,
 		transport::{Boxed, OptionalTransport},
 		upgrade,
 	},
-	dns, identity, mplex, noise, tcp, websocket, PeerId, Transport, TransportExt,
+	dns, identity, noise, tcp, websocket, PeerId, Transport, TransportExt,
 };
 use std::{sync::Arc, time::Duration};
 
@@ -100,10 +99,6 @@ pub fn build_transport(
 		};
 
 	let multiplexing_config = {
-		let mut mplex_config = mplex::MplexConfig::new();
-		mplex_config.set_max_buffer_behaviour(mplex::MaxBufferBehaviour::Block);
-		mplex_config.set_max_buffer_size(usize::MAX);
-
 		let mut yamux_config = libp2p::yamux::YamuxConfig::default();
 		// Enable proper flow-control: window updates are only sent when
 		// buffered data has been consumed.
@@ -114,7 +109,7 @@ pub fn build_transport(
 			yamux_config.set_receive_window_size(yamux_window_size);
 		}
 
-		core::upgrade::SelectUpgrade::new(yamux_config, mplex_config)
+		yamux_config
 	};
 
 	let transport = transport