diff --git a/index.d.ts b/index.d.ts
index 4802aee..422d261 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -487,14 +487,14 @@ interface PdfPackage {
      * @returns []byte of new pdf data
      */
     cpu(
-        command: "watermark" | "stamp",
-        pdfData: any,
-        options: {
+        command: "watermark" | "stamp" | "merge",
+        pdfData: any | any[],
+        options?: {
             pages?: (string | number)[]
             description?: {
                 [key: string]: number | string
             }
-            mode?: "image" | "pdf"
+            mode?: "text" | "image" | "pdf"
             bytes?: any // []byte of watermark image
             file?: string // file for pdf watermark
         }