diff --git a/src/core/Schemas.ts b/src/core/Schemas.ts
index a25b823b2..d3f0256ae 100644
--- a/src/core/Schemas.ts
+++ b/src/core/Schemas.ts
@@ -372,7 +372,7 @@ export const ServerDesyncSchema = ServerBaseMessageSchema.extend({
   yourHash: z.number().optional(),
 });
 
-export const ServerMessageSchema = z.union([
+export const ServerMessageSchema = z.discriminatedUnion("type", [
   ServerTurnMessageSchema,
   ServerPrestartMessageSchema,
   ServerStartGameMessageSchema,
@@ -428,7 +428,7 @@ export const ClientJoinMessageSchema = z.object({
   flag: SafeString.optional(),
 });
 
-export const ClientMessageSchema = z.union([
+export const ClientMessageSchema = z.discriminatedUnion("type", [
   ClientSendWinnerSchema,
   ClientPingMessageSchema,
   ClientIntentMessageSchema,