diff --git a/README.md b/README.md
index 50ec277..e717ee8 100644
--- a/README.md
+++ b/README.md
@@ -99,6 +99,7 @@ TODO
 - Doors in the middle of squares.
 - Rolling doors for `RCL_renderComplex`.
 - Possibly merge all rendering functions into one.
+- Fix rendering bug that happens at the boundary of positive and negative square coords.
 
 license
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