diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_env.c b/drivers/net/ethernet/mellanox/mlxsw/core_env.c
index 7286f0deb5f9..53b150b7ae4e 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_env.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_env.c
@@ -34,7 +34,7 @@ struct mlxsw_env {
 	u8 num_of_slots; /* Including the main board. */
 	u8 max_eeprom_len; /* Maximum module EEPROM transaction length. */
 	struct mutex line_cards_lock; /* Protects line cards. */
-	struct mlxsw_env_line_card *line_cards[];
+	struct mlxsw_env_line_card *line_cards[] __counted_by(num_of_slots);
 };
 
 static bool __mlxsw_env_linecard_is_active(struct mlxsw_env *mlxsw_env,