diff --git a/bin/ethlambda/src/cli.rs b/bin/ethlambda/src/cli.rs
index 848a2446..c0427248 100644
--- a/bin/ethlambda/src/cli.rs
+++ b/bin/ethlambda/src/cli.rs
@@ -50,17 +50,8 @@ pub(crate) struct CliOptions {
     /// over to the next URL. Startup only aborts if every URL fails.
     #[arg(long, value_delimiter = ',')]
     pub(crate) checkpoint_sync_url: Vec<String>,
-    /// Whether this node acts as a committee aggregator.
-    ///
-    /// Seeds the initial value of the live aggregator flag shared by the
-    /// blockchain actor and the admin API. The flag can be toggled at
-    /// runtime via `POST /lean/v0/admin/aggregator`. Runtime toggles do
-    /// NOT persist across restarts and do NOT update gossip subnet
-    /// subscriptions, which are frozen at startup — standby aggregators
-    /// should boot with this flag enabled to establish subscriptions, then
-    /// use the admin endpoint to rotate duties (hot-standby model).
-    #[arg(long, default_value = "false")]
-    pub(crate) is_aggregator: bool,
+    #[command(flatten)]
+    pub(crate) aggregator: AggregatorOpts,
     /// Number of attestation committees (subnets) per slot.
     ///
     /// If unset, falls back to `config.attestation_committee_count` from
@@ -68,10 +59,6 @@ pub(crate) struct CliOptions {
     /// field is also absent.
     #[arg(long, value_parser = clap::value_parser!(u64).range(1..))]
     pub(crate) attestation_committee_count: Option<u64>,
-    /// Subnet IDs this aggregator should subscribe to (comma-separated).
-    /// Requires --is-aggregator. Defaults to the subnets of the node's validators.
-    #[arg(long, value_delimiter = ',', requires = "is_aggregator")]
-    pub(crate) aggregate_subnet_ids: Option<Vec<u64>>,
     /// Directory for RocksDB storage
     #[arg(long, default_value = "./data")]
     pub(crate) data_dir: PathBuf,
@@ -85,3 +72,26 @@ pub(crate) struct CliOptions {
     #[arg(long, default_value = "false")]
     pub(crate) disable_duty_sync_gate: bool,
 }
+
+/// Aggregator-related flags, grouped so the committee-aggregation knobs live
+/// together. Flattened into [`CliOptions`], so the flags stay top-level on the
+/// command line (`--is-aggregator`, `--aggregate-subnet-ids`) and the
+/// `requires` cross-reference still resolves within the parent command.
+#[derive(Debug, clap::Args)]
+pub(crate) struct AggregatorOpts {
+    /// Whether this node acts as a committee aggregator.
+    ///
+    /// Seeds the initial value of the live aggregator flag shared by the
+    /// blockchain actor and the admin API. The flag can be toggled at
+    /// runtime via `POST /lean/v0/admin/aggregator`. Runtime toggles do
+    /// NOT persist across restarts and do NOT update gossip subnet
+    /// subscriptions, which are frozen at startup — standby aggregators
+    /// should boot with this flag enabled to establish subscriptions, then
+    /// use the admin endpoint to rotate duties (hot-standby model).
+    #[arg(long, default_value = "false")]
+    pub(crate) is_aggregator: bool,
+    /// Subnet IDs this aggregator should subscribe to (comma-separated).
+    /// Requires --is-aggregator. Defaults to the subnets of the node's validators.
+    #[arg(long, value_delimiter = ',', requires = "is_aggregator")]
+    pub(crate) aggregate_subnet_ids: Option<Vec<u64>>,
+}
diff --git a/bin/ethlambda/src/main.rs b/bin/ethlambda/src/main.rs
index d85b3e8d..6b4f0835 100644
--- a/bin/ethlambda/src/main.rs
+++ b/bin/ethlambda/src/main.rs
@@ -207,7 +207,7 @@ async fn main() -> eyre::Result<()> {
     // Shared, runtime-mutable aggregator flag. Seeded from the CLI and
     // threaded into both the blockchain actor (which reads on every tick)
     // and the API server (which exposes GET/POST admin endpoints).
-    let aggregator = AggregatorController::new(options.is_aggregator);
+    let aggregator = AggregatorController::new(options.aggregator.is_aggregator);
 
     let blockchain = BlockChain::spawn(
         store.clone(),
@@ -228,8 +228,8 @@ async fn main() -> eyre::Result<()> {
         listening_socket: p2p_socket,
         validator_ids,
         attestation_committee_count,
-        is_aggregator: options.is_aggregator,
-        aggregate_subnet_ids: options.aggregate_subnet_ids,
+        is_aggregator: options.aggregator.is_aggregator,
+        aggregate_subnet_ids: options.aggregator.aggregate_subnet_ids,
     })
     .wrap_err("failed to build swarm")?;