diff --git a/Thirdweb/Thirdweb.Utils/Utils.Types.cs b/Thirdweb/Thirdweb.Utils/Utils.Types.cs
index 0360b97..6933018 100644
--- a/Thirdweb/Thirdweb.Utils/Utils.Types.cs
+++ b/Thirdweb/Thirdweb.Utils/Utils.Types.cs
@@ -1,4 +1,5 @@
 using Newtonsoft.Json;
+using System.Numerics;
 
 namespace Thirdweb;
 
@@ -31,10 +32,10 @@ public class ThirdwebChainData
     public string ShortName { get; set; }
 
     [JsonProperty("chainId")]
-    public int ChainId { get; set; }
+    public BigInteger ChainId { get; set; }
 
     [JsonProperty("networkId")]
-    public int NetworkId { get; set; }
+    public BigInteger NetworkId { get; set; }
 
     [JsonProperty("slug")]
     public string Slug { get; set; }