diff --git a/src/utils/api.ts b/src/utils/api.ts
index f4f4ad5..7bb159f 100644
--- a/src/utils/api.ts
+++ b/src/utils/api.ts
@@ -17,6 +17,15 @@ const getBaseUrl = () => {
   return `http://localhost:${process.env.PORT ?? 3000}`; // dev SSR should use localhost
 };
 
+superjson.registerCustom<Buffer, number[]>(
+  {
+    isApplicable: (v): v is Buffer => v instanceof Buffer,
+    serialize: v => [...v],
+    deserialize: v => Buffer.from(v)
+  },
+  "buffer"
+);
+
 /** A set of type-safe react-query hooks for your tRPC API. */
 export const api = createTRPCNext<AppRouter>({
   config() {