diff --git a/src/sdpd-server.c b/src/sdpd-server.c
index c863508..54de393 100644
--- a/src/sdpd-server.c
+++ b/src/sdpd-server.c
@@ -164,7 +164,7 @@
 	}
 
 	len = recv(sk, &hdr, sizeof(sdp_pdu_hdr_t), MSG_PEEK);
-	if (len != sizeof(sdp_pdu_hdr_t)) {
+	if (len < 0 || (unsigned int) len < sizeof(sdp_pdu_hdr_t)) {
 		sdp_svcdb_collect_all(sk);
 		return FALSE;
 	}