diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 52e1096..9de71bb 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -104,21 +104,22 @@
 
 /* Restore tty state when we exit */
 static struct termios orig_term;
+static bool term_setup;
 
 static void os_fd_restore(void)
 {
-	tcsetattr(0, TCSANOW, &orig_term);
+	if (term_setup)
+		tcsetattr(0, TCSANOW, &orig_term);
 }
 
 /* Put tty into raw mode so <tab> and <ctrl+c> work */
-void os_tty_raw(int fd)
+void os_tty_raw(int fd, bool allow_sigs)
 {
-	static int setup = 0;
 	struct termios term;
 
-	if (setup)
+	if (term_setup)
 		return;
-	setup = 1;
+	term_setup = true;
 
 	/* If not a tty, don't complain */
 	if (tcgetattr(fd, &orig_term))
@@ -128,7 +129,7 @@
 	term.c_iflag = IGNBRK | IGNPAR;
 	term.c_oflag = OPOST | ONLCR;
 	term.c_cflag = CS8 | CREAD | CLOCAL;
-	term.c_lflag = 0;
+	term.c_lflag = allow_sigs ? ISIG : 0;
 	if (tcsetattr(fd, TCSANOW, &term))
 		return;