diff --git a/sbin/hastd/hastd.c b/sbin/hastd/hastd.c
index e47b19d49246..8b59c148d9cf 100644
--- a/sbin/hastd/hastd.c
+++ b/sbin/hastd/hastd.c
@@ -685,6 +685,12 @@ main_loop(void)
 	}
 }
 
+static void
+dummy_sighandler(int sig __unused)
+{
+	/* Nothing to do. */
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -743,6 +749,11 @@ main(int argc, char *argv[])
 	cfg = yy_config_parse(cfgpath, true);
 	assert(cfg != NULL);
 
+	/*
+	 * Because SIGCHLD is ignored by default, setup dummy handler for it,
+	 * so we can mask it.
+	 */
+	PJDLOG_VERIFY(signal(SIGCHLD, dummy_sighandler) != SIG_ERR);
 	PJDLOG_VERIFY(sigemptyset(&mask) == 0);
 	PJDLOG_VERIFY(sigaddset(&mask, SIGHUP) == 0);
 	PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0);