diff --git a/src/erc7730/common/ledger.py b/src/erc7730/common/ledger.py
index c36b436..21c034a 100644
--- a/src/erc7730/common/ledger.py
+++ b/src/erc7730/common/ledger.py
@@ -147,6 +147,8 @@ def ledger_network_id(chain_id: int) -> str | None:
             return "mantle_sepolia"
         case 5031:
             return "somnia"
+        case 5042:
+            return "arc"
         case 6342:
             return "megaeth_testnet"
         case 8217:
@@ -225,6 +227,8 @@ def ledger_network_id(chain_id: int) -> str | None:
             return "id4good"
         case 1313114:
             return "ether1"
+        case 5042002:
+            return "arc_testnet"
         case 7762959:
             return "musicoin"
         case 11155111: