diff --git a/phasm/stdlib/types.py b/phasm/stdlib/types.py
index 7a4d4a6..5c7e46a 100644
--- a/phasm/stdlib/types.py
+++ b/phasm/stdlib/types.py
@@ -39,8 +39,7 @@ def __subscript_bytes__(g: Generator, adr: i32, ofs: i32) -> i32:
     Returns an index from a bytes value
 
     If ofs is more than the length of the bytes, this
-    function returns 0, following the 'no undefined behaviour'
-    philosophy.
+    function stop as unreachable.
 
     adr   i32    The pointer for the allocated bytes
     ofs   i32    The offset within the allocated bytes