diff --git a/speedtest_cli.py b/speedtest_cli.py
index fc08194..51d6335 100755
--- a/speedtest_cli.py
+++ b/speedtest_cli.py
@@ -663,6 +663,19 @@ class Speedtest(object):
             f.close()
 
         extension = re.findall('upload_extension: "([^"]+)"', text.decode())
+        if not extension:
+            for ext in ['php', 'asp', 'aspx', 'jsp']:
+                try:
+                    f = urlopen('%s/speedtest/upload.%s' % (args.mini, ext))
+                except:
+                    pass
+                else:
+                    data = f.read().strip()
+                    if (f.code == 200 and
+                            len(data.splitlines()) == 1 and
+                            re.match('size=[0-9]', data)):
+                        extension = [ext]
+                        break
         if not urlparts or not extension:
             raise InvalidSpeedtestMiniServer('Invalid Speedtest Mini Server: '
                                              '%s' % server)