diff --git a/config/runtime.exs b/config/runtime.exs
index 7787cfd11..20cd528a2 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -90,7 +90,7 @@ config :lambda_ethereum_consensus, LambdaEthereumConsensus.Store.Db, dir: datadi
 
     testnet_dir ->
       Path.join(testnet_dir, "config.yaml") |> CustomConfig.load_from_file!()
-      bootnodes = Path.join(testnet_dir, "boot_enr.yaml") |> YamlElixir.read_from_file!()
+      bootnodes = ConfigUtils.load_testnet_bootnodes(testnet_dir)
       {CustomConfig, bootnodes}
   end
 
@@ -139,8 +139,6 @@ config :lambda_ethereum_consensus, EngineApi,
   version: "2.0"
 
 # Beacon API
-alias BeaconApi
-
 config :lambda_ethereum_consensus, BeaconApi.Endpoint,
   server: enable_beacon_api,
   http: [port: beacon_api_port || 4000],
@@ -168,6 +166,8 @@ block_time_ms =
     "mainnet" -> 12_000
     "sepolia" -> 100
     "holesky" -> 24_000
+    # Default to mainnet
+    _ -> 12_000
   end
 
 config :lambda_ethereum_consensus, LambdaEthereumConsensus.Telemetry,
diff --git a/lib/chain_spec/utils.ex b/lib/chain_spec/utils.ex
index 3f643b6ae..16b1a9fde 100644
--- a/lib/chain_spec/utils.ex
+++ b/lib/chain_spec/utils.ex
@@ -42,4 +42,14 @@ defmodule ConfigUtils do
   def parse_preset("minimal"), do: MinimalPreset
   def parse_preset("gnosis"), do: GnosisPreset
   def parse_preset(other), do: raise("Unknown preset: #{other}")
+
+  def load_testnet_bootnodes(testnet_dir) do
+    bootnodes_file = Path.join(testnet_dir, "boot_enr.yaml")
+
+    if File.exists?(bootnodes_file) do
+      YamlElixir.read_from_file!(bootnodes_file)
+    else
+      []
+    end
+  end
 end
diff --git a/lib/lambda_ethereum_consensus/beacon/beacon_node.ex b/lib/lambda_ethereum_consensus/beacon/beacon_node.ex
index 21305e09c..cdd3917c2 100644
--- a/lib/lambda_ethereum_consensus/beacon/beacon_node.ex
+++ b/lib/lambda_ethereum_consensus/beacon/beacon_node.ex
@@ -23,16 +23,7 @@ defmodule LambdaEthereumConsensus.Beacon.BeaconNode do
 
     Cache.initialize_cache()
 
-    config = Application.fetch_env!(:lambda_ethereum_consensus, :discovery)
-    port = Keyword.fetch!(config, :port)
-    bootnodes = Keyword.fetch!(config, :bootnodes)
-
-    libp2p_args = [
-      listen_addr: [],
-      enable_discovery: true,
-      discovery_addr: "0.0.0.0:#{port}",
-      bootnodes: bootnodes
-    ]
+    libp2p_args = get_libp2p_args()
 
     time = :os.system_time(:second)
 
@@ -86,4 +77,21 @@ defmodule LambdaEthereumConsensus.Beacon.BeaconNode do
       ]
     end
   end
+
+  defp get_libp2p_args() do
+    config = Application.fetch_env!(:lambda_ethereum_consensus, :discovery)
+    port = Keyword.fetch!(config, :port)
+    bootnodes = Keyword.fetch!(config, :bootnodes)
+
+    if Enum.empty?(bootnodes) do
+      Logger.warning("No bootnodes configured.")
+    end
+
+    [
+      listen_addr: [],
+      enable_discovery: true,
+      discovery_addr: "0.0.0.0:#{port}",
+      bootnodes: bootnodes
+    ]
+  end
 end