diff --git a/src/core/Schemas.ts b/src/core/Schemas.ts
index 9f1cd977b..246685b8a 100644
--- a/src/core/Schemas.ts
+++ b/src/core/Schemas.ts
@@ -187,10 +187,7 @@ export const AttackIntentSchema = BaseIntentSchema.extend({
 
 export const SpawnIntentSchema = BaseIntentSchema.extend({
   flag: z.string().optional(),
-  pattern: z
-    .string()
-    .regex(/^[A-Za-z0-9+/=]*$/)
-    .optional(),
+  pattern: z.string().base64().optional(),
   type: z.literal("spawn"),
   name: SafeString,
   playerType: PlayerTypeSchema,