diff --git a/copyparty/mdns.py b/copyparty/mdns.py
index 9fca935a..07f45add 100644
--- a/copyparty/mdns.py
+++ b/copyparty/mdns.py
@@ -329,11 +329,11 @@ class MDNS(MCast):
         if buf in cache.c:
             return
 
-        cache.add(buf)
         srv: Optional[MDNS_Sck] = self.srv[sck] if v6 else self.map_client(cip)  # type: ignore
         if not srv:
             return
 
+        cache.add(buf)
         now = time.time()
 
         if self.args.zmv and cip != srv.ip and cip not in srv.ips:
diff --git a/copyparty/ssdp.py b/copyparty/ssdp.py
index ee97820c..42310f1d 100644
--- a/copyparty/ssdp.py
+++ b/copyparty/ssdp.py
@@ -154,11 +154,11 @@ class SSDPd(MCast):
         if buf in self.rxc.c:
             return
 
-        self.rxc.add(buf)
         srv: Optional[SSDP_Sck] = self.map_client(cip)  # type: ignore
         if not srv:
             return
 
+        self.rxc.add(buf)
         if not buf.startswith(b"M-SEARCH * HTTP/1."):
             raise Exception("not an ssdp message")