diff --git a/README.md b/README.md
index 421e99d..0d09df5 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,7 @@ Very messy and bad, im gonna start the umpteenth rewrite soon.
 
 - [ ] More concise syntax, i dont like how it is right now
 - [ ] Fix stack overflow with recursive functions (internally convert to loops)
+    - [ ] Tail call optimization
 - [ ] Generally implement more 
 - [ ] Implicit multiplication (may not be possible to implement non-ambiguously)
 - [ ] Differentiation