diff --git a/doc/api/buffer.md b/doc/api/buffer.md
index d72e8720c688fa..c07443601c8b67 100644
--- a/doc/api/buffer.md
+++ b/doc/api/buffer.md
@@ -1042,7 +1042,8 @@ in `list` by adding their lengths.
 
 If `totalLength` is provided, it is coerced to an unsigned integer. If the
 combined length of the `Buffer`s in `list` exceeds `totalLength`, the result is
-truncated to `totalLength`.
+truncated to `totalLength`. If the combined length of the `Buffer`s in `list` is
+less than `totalLength`, the remaining space is filled with zeros.
 
 ```mjs
 import { Buffer } from 'node:buffer';