diff --git a/src/programs/pkttyagent.c b/src/programs/pkttyagent.c
index 3c8d502..acbc3ab 100644
--- a/src/programs/pkttyagent.c
+++ b/src/programs/pkttyagent.c
@@ -262,8 +262,11 @@ main (int argc, char *argv[])
tty_flags_saved = TRUE;
}
+
memset (&sa, 0, sizeof (sa));
sa.sa_handler = &tty_handler;
+ sigemptyset(&sa.sa_mask);
+ sigaddset(&sa.sa_mask, SIGTTOU);
sigaction (SIGTERM, &sa, &savesigterm);
sigaction (SIGINT, &sa, &savesigint);
sigaction (SIGTSTP, &sa, &savesigtstp);