diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c
index 0d65587f71aa230ad15982d266eee17a479abbd1..cae6c9411c808edb14a8a69eab788da7e29b7385 100644
--- a/drivers/serial/sandbox.c
+++ b/drivers/serial/sandbox.c
@@ -44,8 +44,7 @@ void serial_putc(const char ch)
 
 void serial_puts(const char *str)
 {
-	while (*str)
-		serial_putc(*str++);
+	os_write(1, str, strlen(str));
 }
 
 int serial_getc(void)