diff --git a/CLIENT-SPECIFICATION.md b/CLIENT-SPECIFICATION.md
index 1e3f1750c8..7ad72de9c9 100644
--- a/CLIENT-SPECIFICATION.md
+++ b/CLIENT-SPECIFICATION.md
@@ -41,7 +41,7 @@ Option             | Required?   | Meaning
 `-l`, `--list`     | No          | Lists all the pages in the current platform to the standard output.
 `-L`, `--language` | No          | Specifies the preferred language for the page returned. Overrides other language detection mechanisms. See the [language section](#language) for more information.
 
-Clients MAY choose to only implement the short version of an option, ignoring the long form.
+Clients MUST implement both the short and long version of an option.
 
 Additional decoration MAY be printed if the standard output is a [TTY](http://www.linusakesson.net/programming/tty/index.php). If not, then the output MUST not contain any additional decorations. For example a page list MUST be formatted with 1 page name per line (to enable easy manipulation using standard CLI tools such as `grep` etc.).
 
@@ -227,8 +227,9 @@ the commit hash changes when merging with squash or rebase.
 -->
 
  - Unreleased
-   -  Add recommendation to support `macos` alias for `osx` ([#7514](https://github.com/tldr-pages/tldr/pull/7514))
-   -  Drop the special "all" platform from `--list` flag ([#7561](https://github.com/tldr-pages/tldr/pull/7561))
+   - Add recommendation to support `macos` alias for `osx` ([#7514](https://github.com/tldr-pages/tldr/pull/7514))
+   - Drop the special "all" platform from `--list` flag ([#7561](https://github.com/tldr-pages/tldr/pull/7561))
+   - Require support for long options ([#9651](https://github.com/tldr-pages/tldr/pull/9651))
 
  - [v1.5, March 17th 2021](https://github.com/tldr-pages/tldr/blob/v1.5/CLIENT-SPECIFICATION.md) ([#5428](https://github.com/tldr-pages/tldr/pull/5428))
    - Add requirement for converting command names to lowercase before running the page resolution algorithm.