diff --git a/client/cli/src/commands/run_cmd.rs b/client/cli/src/commands/run_cmd.rs
index fcc486297b21a..7d3169c077724 100644
--- a/client/cli/src/commands/run_cmd.rs
+++ b/client/cli/src/commands/run_cmd.rs
@@ -127,6 +127,10 @@ pub struct RunCmd {
 	#[structopt(long = "ws-max-connections", value_name = "COUNT")]
 	pub ws_max_connections: Option<usize>,
 
+	/// Set the the maximum WebSocket output buffer size in MiB. Default is 16.
+	#[structopt(long = "ws-max-out-buffer-capacity")]
+	pub ws_max_out_buffer_capacity: Option<usize>,
+
 	/// Size of the RPC HTTP server thread pool.
 	#[structopt(long = "rpc-http-threads", value_name = "COUNT")]
 	pub rpc_http_threads: Option<usize>,
@@ -440,6 +444,10 @@ impl CliConfiguration for RunCmd {
 		Ok(self.rpc_max_payload)
 	}
 
+	fn ws_max_out_buffer_capacity(&self) -> Result<Option<usize>> {
+		Ok(self.ws_max_out_buffer_capacity)
+	}
+
 	fn transaction_pool(&self) -> Result<TransactionPoolOptions> {
 		Ok(self.pool_config.transaction_pool())
 	}
diff --git a/client/cli/src/config.rs b/client/cli/src/config.rs
index bfc7c6eb7bacc..43d4160acd27d 100644
--- a/client/cli/src/config.rs
+++ b/client/cli/src/config.rs
@@ -362,6 +362,11 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 		Ok(None)
 	}
 
+	/// Get maximum WS output buffer capacity.
+	fn ws_max_out_buffer_capacity(&self) -> Result<Option<usize>> {
+		Ok(None)
+	}
+
 	/// Get the prometheus configuration (`None` if disabled)
 	///
 	/// By default this is `None`.
@@ -516,6 +521,7 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 			rpc_http_threads: self.rpc_http_threads()?,
 			rpc_cors: self.rpc_cors(is_dev)?,
 			rpc_max_payload: self.rpc_max_payload()?,
+			ws_max_out_buffer_capacity: self.ws_max_out_buffer_capacity()?,
 			prometheus_config: self.prometheus_config(DCV::prometheus_listen_port())?,
 			telemetry_endpoints,
 			default_heap_pages: self.default_heap_pages()?,
diff --git a/client/rpc-servers/src/lib.rs b/client/rpc-servers/src/lib.rs
index 6e09a0ea36ac0..ad4e4aade7f2f 100644
--- a/client/rpc-servers/src/lib.rs
+++ b/client/rpc-servers/src/lib.rs
@@ -33,6 +33,9 @@ const MEGABYTE: usize = 1024 * 1024;
 /// Maximal payload accepted by RPC servers.
 pub const RPC_MAX_PAYLOAD_DEFAULT: usize = 15 * MEGABYTE;
 
+/// Maximal buffer size in WS server.
+pub const WS_MAX_BUFFER_CAPACITY_DEFAULT: usize = 16 * MEGABYTE;
+
 /// Default maximum number of connections for WS RPC servers.
 const WS_MAX_CONNECTIONS: usize = 100;
 
diff --git a/client/service/src/config.rs b/client/service/src/config.rs
index 4223a1812204e..121091dcade72 100644
--- a/client/service/src/config.rs
+++ b/client/service/src/config.rs
@@ -103,6 +103,8 @@ pub struct Configuration {
 	pub rpc_methods: RpcMethods,
 	/// Maximum payload of rpc request/responses.
 	pub rpc_max_payload: Option<usize>,
+	/// Maximum size of the output buffer capacity for websocket connections.
+	pub ws_max_out_buffer_capacity: Option<usize>,
 	/// Prometheus endpoint configuration. `None` if disabled.
 	pub prometheus_config: Option<PrometheusConfig>,
 	/// Telemetry service URL. `None` if disabled.
diff --git a/client/service/src/lib.rs b/client/service/src/lib.rs
index c8d5a9af35653..fbbfd78f79c09 100644
--- a/client/service/src/lib.rs
+++ b/client/service/src/lib.rs
@@ -437,6 +437,7 @@ fn start_rpc_servers<
 					),
 				)?,
 				config.rpc_max_payload,
+				config.ws_max_out_buffer_capacity,
 				server_metrics.clone(),
 			)
 			.map_err(Error::from)
diff --git a/client/service/test/src/lib.rs b/client/service/test/src/lib.rs
index 61313b4488cb4..ee94fb0c3812e 100644
--- a/client/service/test/src/lib.rs
+++ b/client/service/test/src/lib.rs
@@ -252,6 +252,7 @@ fn node_config<
 		rpc_cors: None,
 		rpc_methods: Default::default(),
 		rpc_max_payload: None,
+		ws_max_out_buffer_capacity: None,
 		prometheus_config: None,
 		telemetry_endpoints: None,
 		default_heap_pages: None,
diff --git a/test-utils/test-runner/src/utils.rs b/test-utils/test-runner/src/utils.rs
index 3caba633dcfa9..9895de81077ff 100644
--- a/test-utils/test-runner/src/utils.rs
+++ b/test-utils/test-runner/src/utils.rs
@@ -99,6 +99,7 @@ pub fn default_config(
 		rpc_cors: None,
 		rpc_methods: Default::default(),
 		rpc_max_payload: None,
+		ws_max_out_buffer_capacity: None,
 		prometheus_config: None,
 		telemetry_endpoints: None,
 		default_heap_pages: None,