diff --git a/weed/s3api/filer_multipart.go b/weed/s3api/filer_multipart.go
index 1e4635ead..8dca4cedc 100644
--- a/weed/s3api/filer_multipart.go
+++ b/weed/s3api/filer_multipart.go
@@ -187,7 +187,10 @@ func (s3a *S3ApiServer) completeMultipartUpload(r *http.Request, input *s3.Compl
 	sort.Ints(completedPartNumbers)
 
 	uploadDirectory := s3a.genUploadsFolder(*input.Bucket) + "/" + *input.UploadId
-	entries, _, err := s3a.list(uploadDirectory, "", "", false, 0)
+	// Use explicit limit to ensure all parts are listed (up to S3's max of 10,000 parts)
+	// Previously limit=0 relied on server's DirListingLimit default (1000 in weed server mode),
+	// which caused CompleteMultipartUpload to fail for uploads with more than 1000 parts.
+	entries, _, err := s3a.list(uploadDirectory, "", "", false, s3_constants.MaxS3MultipartParts+1)
 	if err != nil {
 		glog.Errorf("completeMultipartUpload %s %s error: %v, entries:%d", *input.Bucket, *input.UploadId, err, len(entries))
 		stats.S3HandlerCounter.WithLabelValues(stats.ErrorCompletedNoSuchUpload).Inc()