diff --git a/skynet-src/skynet_daemon.c b/skynet-src/skynet_daemon.c
index 902086e3..8cb7faae 100644
--- a/skynet-src/skynet_daemon.c
+++ b/skynet-src/skynet_daemon.c
@@ -37,7 +37,7 @@ write_pid(const char *pidfile) {
 		fprintf(stderr, "Can't create pidfile [%s].\n", pidfile);
 		return 0;
 	}
-	f = fdopen(fd, "r+");
+	f = fdopen(fd, "w+");
 	if (f == NULL) {
 		fprintf(stderr, "Can't open pidfile [%s].\n", pidfile);
 		return 0;