diff --git a/crates/nvlink-manager/src/lib.rs b/crates/nvlink-manager/src/lib.rs
index 2bf0d987fa..821436b019 100644
--- a/crates/nvlink-manager/src/lib.rs
+++ b/crates/nvlink-manager/src/lib.rs
@@ -62,9 +62,10 @@ use tracing::Instrument;
 /// Default NMX-M instance identifier for credentials and client lookup when none is specified.
 pub const DEFAULT_NMX_M_NAME: &str = "default";
 
-/// Multicast groups limit for new NMX-C partitions. Assuming at most 2 partitions per tray and
-// 18 tray default partitions, this is set to floor(1024 / (36+18)).
-const NMX_C_PARTITION_MULTICAST_GROUPS_LIMIT: u32 = 1024 / (36 + 18);
+/// Multicast groups limit for new NMX-C partitions. Must be a multiple of 4. Assuming at most 2
+/// partitions per tray and 18 tray default partitions, this is floor(1024 / (36+18)) rounded down
+/// to the nearest multiple of 4.
+const NMX_C_PARTITION_MULTICAST_GROUPS_LIMIT: u32 = 16;
 
 fn rack_id_from_chassis_snapshots(
     chassis_snapshots: &[&ManagedHostStateSnapshot],