diff --git a/circuit/README.md b/circuit/README.md
index 22d35c6..16b11ff 100644
--- a/circuit/README.md
+++ b/circuit/README.md
@@ -4,6 +4,7 @@
 
 ### TODO
 
+- Expand ptr to 15 bits to match the 30000 cells of brainfuck
 - Expand return address register to stack
 - Implement memory as in- and output for more complex in- and output programs