diff --git a/packages/prisma/zod-utils.ts b/packages/prisma/zod-utils.ts
index 3f298a8282..0475505e35 100644
--- a/packages/prisma/zod-utils.ts
+++ b/packages/prisma/zod-utils.ts
@@ -374,7 +374,7 @@ export const bookingCancelSchema = z.object({
     .object({
       id: z.number(),
       name: z.string(),
-      cancellationReason: z.string().optional(),
+      cancellationReason: z.string().optional().nullable(),
     })
     .optional()
     .nullable(),