diff --git a/ssdp.py b/ssdp.py
index 32a91df..ba23ee2 100644
--- a/ssdp.py
+++ b/ssdp.py
@@ -82,7 +82,8 @@
 
         # ST: urn:schemas-upnp-org:device:MediaServer:1
         if m.group(1) == 'ST':
-          parsed_data['discovery_type'] = m.group(2).split(':')[3]
+          if m.group(2).startswith('urn:schemas-upnp-org:device:'):
+            parsed_data['discovery_type'] = m.group(2).split(':')[3]
 
     return parsed_data