diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index ac05afd3f1655999373f11cab873ccda21fda057..480688b71c758e09510e8ad3bb6f2030fdf2a458 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -26,7 +26,7 @@
  * Byte threshold to limit memory consumption for flip buffers.
  * The actual memory limit is > 2x this amount.
  */
-#define TTYB_DEFAULT_MEM_LIMIT	65536
+#define TTYB_DEFAULT_MEM_LIMIT	(640 * 1024UL)
 
 /*
  * We default to dicing tty buffer allocations to this many characters