diff --git a/src/lib/api.ts b/src/lib/api.ts
index 8fb382e..48657c7 100644
--- a/src/lib/api.ts
+++ b/src/lib/api.ts
@@ -425,6 +425,8 @@ export type PreviewInput = {
   realistic?: boolean;
   envelope_labeling?: string;
   envelope_text?: string;
+  /** Textmengencheck: unbegrenzt, ohne Vorschau-Kontingent. */
+  check?: boolean;
   entries: unknown[];
 };
 
diff --git a/src/routes/Textmenge.tsx b/src/routes/Textmenge.tsx
index 8124c64..f990a34 100644
--- a/src/routes/Textmenge.tsx
+++ b/src/routes/Textmenge.tsx
@@ -187,6 +187,7 @@ export default function Textmenge() {
         font,
         format: formatKey,
         realistic,
+        check: true,
         entries: [{}],
       });
       if (ergebnis.has_overflow) {