diff --git a/src/sock.c b/src/sock.c
index a60c406..0351dfc 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -529,8 +529,10 @@ ssize_t patty_ax25_sock_send_xid(patty_ax25_sock *sock,
 
     ssize_t encoded;
 
-    if (sock->remote.callsign[0] == '\0') {
-        goto error_nopeer;
+    if (sock->iface == NULL) {
+        errno = ENETDOWN;
+
+        goto error_noif;
     }
 
     params.flags = (1 << PATTY_AX25_PARAM_CLASSES)
@@ -558,7 +560,7 @@ ssize_t patty_ax25_sock_send_xid(patty_ax25_sock *sock,
                                 encoded);
 
 error_frame_encode_xid:
-error_nopeer:
+error_noif:
     return -1;
 }