diff --git a/WalletConnectSharp.Sign/Engine.cs b/WalletConnectSharp.Sign/Engine.cs
index 8006a5d..411e6e6 100644
--- a/WalletConnectSharp.Sign/Engine.cs
+++ b/WalletConnectSharp.Sign/Engine.cs
@@ -683,7 +683,7 @@ public async Task<TR> Request<T, TR>(string topic, T data, string chainId = null
             if (string.IsNullOrWhiteSpace(chainId))
             {
                 var sessionData = Client.Session.Get(topic);
-                var firstRequiredNamespace = sessionData.RequiredNamespaces.OrderedKeys[0];
+                var firstRequiredNamespace = sessionData.RequiredNamespaces.Keys.First();
                 defaultChainId = sessionData.RequiredNamespaces[firstRequiredNamespace].Chains[0];
             }
             else