diff --git a/disk/Aliyundrive.php b/disk/Aliyundrive.php
index 6d0881a..0d577e8 100644
--- a/disk/Aliyundrive.php
+++ b/disk/Aliyundrive.php
@@ -573,7 +573,7 @@ class Aliyundrive {
         } else {
             if (isset($_POST['CalcProof'])&&is_numeric($_POST['filesize'])) {
                 // Calc proof code
-                if (!function_exists('hexdec')) {
+                if (!function_exists('bcadd')) {
                     // no php-bcmath
                     return output(0, 200);
                 } else {
@@ -614,8 +614,11 @@ class Aliyundrive {
                 //error_log1($res['body']);
                 $parent_file_id = json_decode($res['body'], true)['file_id'];
             }
-            //$response = $this->fileCreate($parent_file_id, $filename, $_POST['filesha1'], $fileinfo['size'], ceil($fileinfo['size']/$_POST['chunksize']));
-            $response = $this->fileCreate1($parent_file_id, $filename, $_POST['filesha1'], $_POST['proof_code'], $fileinfo['size'], ceil($fileinfo['size']/$_POST['chunksize']));
+            if (!function_exists('bcadd')) {
+                $response = $this->fileCreate($parent_file_id, $filename, $_POST['filesha1'], $fileinfo['size'], ceil($fileinfo['size']/$_POST['chunksize']));
+            } else {
+                $response = $this->fileCreate1($parent_file_id, $filename, $_POST['filesha1'], $_POST['proof_code'], $fileinfo['size'], ceil($fileinfo['size']/$_POST['chunksize']));
+            }
             $res = json_decode($response['body'], true);
             if (isset($res['exist'])) {
                 // 已经有