diff --git a/subjects/cut-corners/README.md b/subjects/cut-corners/README.md
index 5e36ba8b..bd4d823a 100644
--- a/subjects/cut-corners/README.md
+++ b/subjects/cut-corners/README.md
@@ -12,6 +12,7 @@ Create some functions which behave like JavaScript's `Math` rounding functions:
 > Some restrictions apply:
 > - You may not use strings conversion to do it
 > - No bitwise operator
+> - No `%` operator
 
 ### Notions