diff --git a/iohandler.c b/iohandler.c
index ae2ef8f9669d..cca614f087f6 100644
--- a/iohandler.c
+++ b/iohandler.c
@@ -191,6 +191,7 @@ static void qemu_init_child_watch(void)
     struct sigaction act;
     sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL);
 
+    memset(&act, 0, sizeof(act));
     act.sa_handler = sigchld_handler;
     act.sa_flags = SA_NOCLDSTOP;
     sigaction(SIGCHLD, &act, NULL);