diff --git a/README.md b/README.md
index 5e0acbe..fdeb7c3 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ The example folder contains input and output files for two simple test systems:
 
 TODO
 ---
+- calculate bin count only once
 - Multithreading (?)
 - Error analysis / bootstrapping
 - Better error messages during file I/O