diff --git a/README.md b/README.md
index f11f3dd..76a2bf4 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,7 @@ Completed:
 
 In progress:
 
+* larger stack size, current stack size is only about 60, 250 or so would be better
 * emulation of serial ports to allow standard I/O
 * a unit test suite to ensure each instruction is correct
 * a proof-of-concept application