diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c
index 9e9bf3e..4a05ea4 100644
--- a/drivers/serial/sandbox.c
+++ b/drivers/serial/sandbox.c
@@ -126,7 +126,7 @@
 	if (next_index == serial_buf_read)
 		return 1;	/* buffer full */
 
-	count = os_read_no_block(0, &serial_buf[serial_buf_write], 1);
+	count = os_read(0, &serial_buf[serial_buf_write], 1);
 	if (count == 1)
 		serial_buf_write = next_index;