diff --git a/bin/ethlambda/src/main.rs b/bin/ethlambda/src/main.rs
index bc5c9a1..f23ea58 100644
--- a/bin/ethlambda/src/main.rs
+++ b/bin/ethlambda/src/main.rs
@@ -54,6 +54,9 @@ struct CliOptions {
     /// Whether this node acts as a committee aggregator
     #[arg(long, default_value = "false")]
     is_aggregator: bool,
+    /// Number of attestation committees (subnets) per slot
+    #[arg(long, default_value = "1", value_parser = clap::value_parser!(u64).range(1..))]
+    attestation_committee_count: u64,
 }
 
 #[tokio::main]
@@ -130,6 +133,7 @@ async fn main() -> eyre::Result<()> {
         p2p_rx,
         store.clone(),
         first_validator_id,
+        options.attestation_committee_count,
     ));
 
     ethlambda_rpc::start_rpc_server(metrics_socket, store)
diff --git a/crates/blockchain/src/lib.rs b/crates/blockchain/src/lib.rs
index d30c72e..ad0b9ea 100644
--- a/crates/blockchain/src/lib.rs
+++ b/crates/blockchain/src/lib.rs
@@ -48,9 +48,6 @@ pub const MILLISECONDS_PER_SLOT: u64 = 4_000;
 pub const MILLISECONDS_PER_INTERVAL: u64 = 800;
 /// Number of intervals per slot (5 intervals of 800ms = 4 seconds).
 pub const INTERVALS_PER_SLOT: u64 = 5;
-/// Number of attestation committees per slot.
-pub const ATTESTATION_COMMITTEE_COUNT: u64 = 1;
-
 impl BlockChain {
     pub fn spawn(
         store: Store,
diff --git a/crates/net/p2p/src/lib.rs b/crates/net/p2p/src/lib.rs
index 697fa6d..4e2a465 100644
--- a/crates/net/p2p/src/lib.rs
+++ b/crates/net/p2p/src/lib.rs
@@ -4,7 +4,7 @@ use std::{
     time::Duration,
 };
 
-use ethlambda_blockchain::{ATTESTATION_COMMITTEE_COUNT, BlockChain, P2PMessage};
+use ethlambda_blockchain::{BlockChain, P2PMessage};
 use ethlambda_storage::Store;
 use ethlambda_types::primitives::H256;
 use ethrex_common::H264;
@@ -56,6 +56,7 @@ pub(crate) struct PendingRequest {
     pub(crate) last_peer: Option<PeerId>,
 }
 
+#[allow(clippy::too_many_arguments)]
 pub async fn start_p2p(
     node_key: Vec<u8>,
     bootnodes: Vec<Bootnode>,
@@ -64,6 +65,7 @@ pub async fn start_p2p(
     p2p_rx: mpsc::UnboundedReceiver<P2PMessage>,
     store: Store,
     validator_id: Option<u64>,
+    attestation_committee_count: u64,
 ) {
     let config = libp2p::gossipsub::ConfigBuilder::default()
         // d
@@ -175,9 +177,8 @@ pub async fn start_p2p(
         .unwrap();
 
     // Subscribe to attestation subnet topic (validators subscribe to their committee's subnet)
-    // ATTESTATION_COMMITTEE_COUNT is 1 for devnet-3 but will increase in future devnets.
-    #[allow(clippy::modulo_one)]
-    let subnet_id = validator_id.map(|vid| vid % ATTESTATION_COMMITTEE_COUNT);
+    // attestation_committee_count is validated to be >= 1 by clap at CLI parse time.
+    let subnet_id = validator_id.map(|vid| vid % attestation_committee_count);
     let attestation_topic_kind = match subnet_id {
         Some(id) => format!("{ATTESTATION_SUBNET_TOPIC_PREFIX}_{id}"),
         // Non-validators subscribe to subnet 0 to receive attestations