diff --git a/event.c b/event.c
index c64a66de..575f8f52 100644
--- a/event.c
+++ b/event.c
@@ -1127,7 +1127,7 @@ event_signal_closure(struct event_base *base, struct event *ev)
 		ev->ev_ncalls = ncalls;
 		if (ncalls == 0)
 			ev->ev_pncalls = NULL;
-		(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_arg);
+		(*ev->ev_callback)(ev->ev_fd, ev->ev_res, ev->ev_arg);
 
 		EVBASE_ACQUIRE_LOCK(base, th_base_lock);
 		should_break = base->event_break;
@@ -1358,7 +1358,7 @@ event_persist_closure(struct event_base *base, struct event *ev)
 		event_add_internal(ev, &run_at, 1);
 	}
 	EVBASE_RELEASE_LOCK(base, th_base_lock);
-	(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_arg);
+	(*ev->ev_callback)(ev->ev_fd, ev->ev_res, ev->ev_arg);
 }
 
 /*
@@ -1409,7 +1409,7 @@ event_process_active_single_queue(struct event_base *base,
 		case EV_CLOSURE_NONE:
 			EVBASE_RELEASE_LOCK(base, th_base_lock);
 			(*ev->ev_callback)(
-				(int)ev->ev_fd, ev->ev_res, ev->ev_arg);
+				ev->ev_fd, ev->ev_res, ev->ev_arg);
 			break;
 		}
 
diff --git a/listener.c b/listener.c
index 388b3327..9b68cc0d 100644
--- a/listener.c
+++ b/listener.c
@@ -392,6 +392,12 @@ listener_read_cb(evutil_socket_t fd, short what, void *p)
 		evutil_socket_t new_fd = accept(fd, (struct sockaddr*)&ss, &socklen);
 		if (new_fd < 0)
 			break;
+		if (socklen == 0) {
+			/* This can happen with some older linux kernels in
+			 * response to nmap. */
+			evutil_closesocket(new_fd);
+			continue;
+		}
 
 		if (!(lev->flags & LEV_OPT_LEAVE_SOCKETS_BLOCKING))
 			evutil_make_socket_nonblocking(new_fd);