diff --git a/.changeset/chilled-crews-vanish.md b/.changeset/chilled-crews-vanish.md
new file mode 100644
index 000000000..4d4ad4abe
--- /dev/null
+++ b/.changeset/chilled-crews-vanish.md
@@ -0,0 +1,5 @@
+---
+'@reservoir0x/relay-sdk': patch
+---
+
+Fix typescript error in RelayChain
diff --git a/packages/sdk/src/types/RelayChain.ts b/packages/sdk/src/types/RelayChain.ts
index 840deefc9..55b9655fa 100644
--- a/packages/sdk/src/types/RelayChain.ts
+++ b/packages/sdk/src/types/RelayChain.ts
@@ -35,5 +35,5 @@ export type RelayChain = {
   logoUrl?: string | null
   brandColor?: string | null
   vmType?: ChainVM
-  viemChain: Chain
+  viemChain?: Chain
 }
diff --git a/packages/sdk/src/utils/viemWallet.ts b/packages/sdk/src/utils/viemWallet.ts
index 9523ed58c..bdc03e685 100644
--- a/packages/sdk/src/utils/viemWallet.ts
+++ b/packages/sdk/src/utils/viemWallet.ts
@@ -140,7 +140,7 @@ export const adaptViemWallet = (wallet: WalletClient): AdaptedWallet => {
           throw 'Chain missing from Relay Client'
         }
         await wallet.addChain({
-          chain: chain?.viemChain
+          chain: chain?.viemChain!
         })
         return
       }