diff --git a/scripts/wx_download.lua b/scripts/wx_download.lua
index af17aae..29d642e 100644
--- a/scripts/wx_download.lua
+++ b/scripts/wx_download.lua
@@ -69,7 +69,7 @@ local function get_wx_media(media_id)
         ngx.exit(res.status)
     end
 
-    local filename = ngx.re.match(res.headers['Content-disposition'], [[filename="(.+\.(amr|speex))"]], "jo")[1]
+    local filename = ngx.re.match(res.headers['Content-disposition'], [[filename="(.+\.([a-zA-Z0-9)+)"]], "jo")[1]
     local file_dir = ngx.var.tmp_file_dir
     local saved_file = file_dir .. "/" .. filename;
     print('saved file...' .. saved_file);